Merge Chromium at 7.0.540.0 : Initial merge by git

Not including third_party/icu as it contains huge data files that break Gerrit, and aren't actually used.

Change-Id: I428a386e70f3b58cacd28677b8cfda282e891e15

60 files changed, 2971 insertions, 772 deletions

diff --git a/chrome/browser/history/archived_database.cc b/chrome/browser/history/archived_database.cc
index 1b9e010..72fa998 100644
--- a/chrome/browser/history/archived_database.cc
+++ b/chrome/browser/history/archived_database.cc
@@ -5,7 +5,6 @@
 #include <algorithm>
 #include <string>
 
-#include "app/sql/statement.h"
 #include "app/sql/transaction.h"
 #include "base/string_util.h"
 #include "chrome/browser/history/archived_database.h"
@@ -14,7 +13,7 @@ namespace history {
 
 namespace {
 
-static const int kCurrentVersionNumber = 2;
+static const int kCurrentVersionNumber = 3;
 static const int kCompatibleVersionNumber = 2;
 
 }  // namespace
@@ -111,6 +110,12 @@ sql::InitStatus ArchivedDatabase::EnsureCurrentVersion() {
         std::min(cur_version, kCompatibleVersionNumber));
   }
 
+  if (cur_version == 2) {
+    // This is the version prior to adding visit_source table.
+    ++cur_version;
+    meta_table_.SetVersionNumber(cur_version);
+  }
+
   // Put future migration cases here.
 
   // When the version is too old, we just try to continue anyway, there should
diff --git a/chrome/browser/history/archived_database.h b/chrome/browser/history/archived_database.h
index c9d8757..9568aa5 100644
--- a/chrome/browser/history/archived_database.h
+++ b/chrome/browser/history/archived_database.h
@@ -4,6 +4,7 @@
 
 #ifndef CHROME_BROWSER_HISTORY_ARCHIVED_DATABASE_H_
 #define CHROME_BROWSER_HISTORY_ARCHIVED_DATABASE_H_
+#pragma once
 
 #include "app/sql/connection.h"
 #include "app/sql/init_status.h"
diff --git a/chrome/browser/history/download_database.cc b/chrome/browser/history/download_database.cc
index aa3dbde..f101e39 100644
--- a/chrome/browser/history/download_database.cc
+++ b/chrome/browser/history/download_database.cc
@@ -7,13 +7,12 @@
 #include <limits>
 #include <vector>
 
-#include "app/sql/connection.h"
 #include "app/sql/statement.h"
 #include "base/file_path.h"
 #include "base/utf_string_conversions.h"
 #include "build/build_config.h"
 #include "chrome/browser/download/download_item.h"
-#include "chrome/browser/history/download_types.h"
+#include "chrome/browser/history/download_create_info.h"
 
 // Download schema:
 //
@@ -197,22 +196,4 @@ void DownloadDatabase::RemoveDownloadsBetween(base::Time delete_begin,
   statement.Run();
 }
 
-void DownloadDatabase::SearchDownloads(std::vector<int64>* results,
-                                       const string16& search_text) {
-  sql::Statement statement(GetDB().GetCachedStatement(SQL_FROM_HERE,
-      "SELECT id FROM downloads WHERE url LIKE ? "
-      "OR full_path LIKE ? ORDER BY id"));
-  if (!statement)
-    return;
-
-  std::string text("%");
-  text.append(UTF16ToUTF8(search_text));
-  text.push_back('%');
-  statement.BindString(0, text);
-  statement.BindString(1, text);
-
-  while (statement.Step())
-    results->push_back(statement.ColumnInt64(0));
-}
-
 }  // namespace history
diff --git a/chrome/browser/history/download_database.h b/chrome/browser/history/download_database.h
index 11adf31..56f650a 100644
--- a/chrome/browser/history/download_database.h
+++ b/chrome/browser/history/download_database.h
@@ -4,6 +4,7 @@
 
 #ifndef CHROME_BROWSER_HISTORY_DOWNLOAD_DATABASE_H_
 #define CHROME_BROWSER_HISTORY_DOWNLOAD_DATABASE_H_
+#pragma once
 
 #include "chrome/browser/history/history_types.h"
 
@@ -50,10 +51,6 @@ class DownloadDatabase {
   // all downloads that are in progress or are waiting to be cancelled.
   void RemoveDownloadsBetween(base::Time remove_begin, base::Time remove_end);
 
-  // Search for downloads matching the search text.
-  void SearchDownloads(std::vector<int64>* results,
-                       const string16& search_text);
-
  protected:
   // Returns the database for the functions in this interface.
   virtual sql::Connection& GetDB() = 0;
diff --git a/chrome/browser/history/download_types.h b/chrome/browser/history/download_types.h
deleted file mode 100644
index 642ac5b..0000000
--- a/chrome/browser/history/download_types.h
+++ /dev/null
@@ -1,104 +0,0 @@
-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-//
-// Download creation struct used for querying the history service.
-
-#ifndef CHROME_BROWSER_HISTORY_DOWNLOAD_TYPES_H_
-#define CHROME_BROWSER_HISTORY_DOWNLOAD_TYPES_H_
-
-#include <string>
-
-#include "base/basictypes.h"
-#include "base/file_path.h"
-#include "base/time.h"
-#include "chrome/browser/download/download_file.h"
-#include "googleurl/src/gurl.h"
-
-// Used for informing the download database of a new download, where we don't
-// want to pass DownloadItems between threads. The history service also uses a
-// vector of these structs for passing us the state of all downloads at
-// initialization time (see DownloadQueryInfo below).
-struct DownloadCreateInfo {
-  DownloadCreateInfo(const FilePath& path,
-                     const GURL& url,
-                     base::Time start_time,
-                     int64 received_bytes,
-                     int64 total_bytes,
-                     int32 state,
-                     int32 download_id)
-      : path(path),
-        url(url),
-        path_uniquifier(0),
-        start_time(start_time),
-        received_bytes(received_bytes),
-        total_bytes(total_bytes),
-        state(state),
-        download_id(download_id),
-        child_id(-1),
-        render_view_id(-1),
-        request_id(-1),
-        db_handle(0),
-        prompt_user_for_save_location(false),
-        is_dangerous(false),
-        is_extension_install(false) {
-  }
-
-  DownloadCreateInfo()
-      : path_uniquifier(0),
-        received_bytes(0),
-        total_bytes(0),
-        state(-1),
-        download_id(-1),
-        child_id(-1),
-        render_view_id(-1),
-        request_id(-1),
-        db_handle(0),
-        prompt_user_for_save_location(false),
-        is_dangerous(false),
-        is_extension_install(false) {
-  }
-
-  // DownloadItem fields
-  FilePath path;
-  GURL url;
-  GURL referrer_url;
-  FilePath suggested_path;
-  // A number that should be added to the suggested path to make it unique.
-  // 0 means no number should be appended.  Not actually stored in the db.
-  int path_uniquifier;
-  base::Time start_time;
-  int64 received_bytes;
-  int64 total_bytes;
-  int32 state;
-  int32 download_id;
-  int child_id;
-  int render_view_id;
-  int request_id;
-  int64 db_handle;
-  std::string content_disposition;
-  std::string mime_type;
-  // The value of the content type header sent with the downloaded item.  It
-  // may be different from |mime_type|, which may be set based on heuristics
-  // which may look at the file extension and first few bytes of the file.
-  std::string original_mime_type;
-
-  // True if we should display the 'save as...' UI and prompt the user
-  // for the download location.
-  // False if the UI should be supressed and the download performed to the
-  // default location.
-  bool prompt_user_for_save_location;
-  // Whether this download is potentially dangerous (ex: exe, dll, ...).
-  bool is_dangerous;
-  // The original name for a dangerous download.
-  FilePath original_name;
-  // Whether this download is for extension install or not.
-  bool is_extension_install;
-  // The charset of the referring page where the download request comes from.
-  // It's used to construct a suggested filename.
-  std::string referrer_charset;
-  // The download file save info.
-  DownloadSaveInfo save_info;
-};
-
-#endif  // CHROME_BROWSER_HISTORY_DOWNLOAD_TYPES_H_
diff --git a/chrome/browser/history/expire_history_backend.cc b/chrome/browser/history/expire_history_backend.cc
index bd471ad..294c0e6 100644
--- a/chrome/browser/history/expire_history_backend.cc
+++ b/chrome/browser/history/expire_history_backend.cc
@@ -512,7 +512,7 @@ void ExpireHistoryBackend::ExpireURLsForVisits(
 void ExpireHistoryBackend::ArchiveURLsAndVisits(
     const VisitVector& visits,
     DeleteDependencies* dependencies) {
-  if (!archived_db_)
+  if (!archived_db_ || !main_db_)
     return;
 
   // Make sure all unique URL rows are added to the dependency list and the
@@ -539,6 +539,12 @@ void ExpireHistoryBackend::ArchiveURLsAndVisits(
     }
   }
 
+  // Retrieve the sources for all the archived visits before archiving.
+  // The returned visit_sources vector should contain the source for each visit
+  // from visits at the same index.
+  VisitSourceMap visit_sources;
+  main_db_->GetVisitsSource(visits, &visit_sources);
+
   // Now archive the visits since we know the URL ID to make them reference.
   // The source visit list should still reference the visits in the main DB, but
   // we will update it to reflect only the visits that were successfully
@@ -550,7 +556,9 @@ void ExpireHistoryBackend::ArchiveURLsAndVisits(
     VisitRow cur_visit(visits[i]);
     cur_visit.url_id = main_id_to_archived_id[cur_visit.url_id];
     cur_visit.referring_visit = 0;
-    archived_db_->AddVisit(&cur_visit);
+    VisitSourceMap::iterator iter = visit_sources.find(visits[i].visit_id);
+    archived_db_->AddVisit(&cur_visit,
+        iter == visit_sources.end() ? SOURCE_BROWSED : iter->second);
     // Ignore failures, we will delete it from the main DB no matter what.
   }
 }
diff --git a/chrome/browser/history/expire_history_backend.h b/chrome/browser/history/expire_history_backend.h
index 9f060ed..96e2e9a 100644
--- a/chrome/browser/history/expire_history_backend.h
+++ b/chrome/browser/history/expire_history_backend.h
@@ -4,6 +4,7 @@
 
 #ifndef CHROME_BROWSER_HISTORY_EXPIRE_HISTORY_BACKEND_H_
 #define CHROME_BROWSER_HISTORY_EXPIRE_HISTORY_BACKEND_H_
+#pragma once
 
 #include <queue>
 #include <set>
@@ -105,6 +106,7 @@ class ExpireHistoryBackend {
   FRIEND_TEST_ALL_PREFIXES(ExpireHistoryTest, DeleteFaviconsIfPossible);
   FRIEND_TEST_ALL_PREFIXES(ExpireHistoryTest, ArchiveSomeOldHistory);
   FRIEND_TEST_ALL_PREFIXES(ExpireHistoryTest, ExpiringVisitsReader);
+  FRIEND_TEST_ALL_PREFIXES(ExpireHistoryTest, ArchiveSomeOldHistoryWithSource);
   friend class ::TestingProfile;
 
   struct DeleteDependencies;
diff --git a/chrome/browser/history/expire_history_backend_unittest.cc b/chrome/browser/history/expire_history_backend_unittest.cc
index ca822bc..91129ed 100644
--- a/chrome/browser/history/expire_history_backend_unittest.cc
+++ b/chrome/browser/history/expire_history_backend_unittest.cc
@@ -8,6 +8,7 @@
 #include "base/file_util.h"
 #include "base/path_service.h"
 #include "base/scoped_ptr.h"
+#include "base/string16.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/bookmarks/bookmark_model.h"
 #include "chrome/browser/history/archived_database.h"
@@ -16,8 +17,10 @@
 #include "chrome/browser/history/history_notifications.h"
 #include "chrome/browser/history/text_database_manager.h"
 #include "chrome/browser/history/thumbnail_database.h"
+#include "chrome/browser/history/top_sites.h"
 #include "chrome/common/notification_service.h"
 #include "chrome/common/thumbnail_score.h"
+#include "chrome/test/testing_profile.h"
 #include "chrome/tools/profiles/thumbnail-inl.h"
 #include "gfx/codec/jpeg_codec.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -53,6 +56,8 @@ class ExpireHistoryTest : public testing::Test,
  protected:
   // Called by individual tests when they want data populated.
   void AddExampleData(URLID url_ids[3], Time visit_times[4]);
+  // Add visits with source information.
+  void AddExampleSourceData(const GURL& url, URLID* id);
 
   // Returns true if the given favicon/thumanil has an entry in the DB.
   bool HasFavIcon(FavIconID favicon_id);
@@ -75,7 +80,7 @@ class ExpireHistoryTest : public testing::Test,
 
   void StarURL(const GURL& url) {
     bookmark_model_.AddURL(
-        bookmark_model_.GetBookmarkBarNode(), 0, std::wstring(), url);
+        bookmark_model_.GetBookmarkBarNode(), 0, string16(), url);
   }
 
   static bool IsStringInFile(const FilePath& filename, const char* str);
@@ -90,6 +95,8 @@ class ExpireHistoryTest : public testing::Test,
   scoped_ptr<ArchivedDatabase> archived_db_;
   scoped_ptr<ThumbnailDatabase> thumb_db_;
   scoped_ptr<TextDatabaseManager> text_db_;
+  TestingProfile profile_;
+  scoped_refptr<TopSites> top_sites_;
 
   // Time at the beginning of the test, so everybody agrees what "now" is.
   const Time now_;
@@ -134,6 +141,7 @@ class ExpireHistoryTest : public testing::Test,
 
     expirer_.SetDatabases(main_db_.get(), archived_db_.get(), thumb_db_.get(),
                           text_db_.get());
+    top_sites_ = profile_.GetTopSites();
   }
 
   void TearDown() {
@@ -145,6 +153,7 @@ class ExpireHistoryTest : public testing::Test,
     archived_db_.reset();
     thumb_db_.reset();
     text_db_.reset();
+    TopSites::DeleteTopSites(top_sites_);
     file_util::Delete(dir_, true);
   }
 
@@ -211,35 +220,35 @@ void ExpireHistoryTest::AddExampleData(URLID url_ids[3], Time visit_times[4]) {
 
   Time time;
   GURL gurl;
-  thumb_db_->SetPageThumbnail(gurl, url_ids[0], *thumbnail, score, time);
-  thumb_db_->SetPageThumbnail(gurl, url_ids[1], *thumbnail, score, time);
-  thumb_db_->SetPageThumbnail(gurl, url_ids[2], *thumbnail, score, time);
+  top_sites_->SetPageThumbnail(url_row1.url(), *thumbnail, score);
+  top_sites_->SetPageThumbnail(url_row2.url(), *thumbnail, score);
+  top_sites_->SetPageThumbnail(url_row3.url(), *thumbnail, score);
 
   // Four visits.
   VisitRow visit_row1;
   visit_row1.url_id = url_ids[0];
   visit_row1.visit_time = visit_times[0];
   visit_row1.is_indexed = true;
-  main_db_->AddVisit(&visit_row1);
+  main_db_->AddVisit(&visit_row1, SOURCE_BROWSED);
 
   VisitRow visit_row2;
   visit_row2.url_id = url_ids[1];
   visit_row2.visit_time = visit_times[1];
   visit_row2.is_indexed = true;
-  main_db_->AddVisit(&visit_row2);
+  main_db_->AddVisit(&visit_row2, SOURCE_BROWSED);
 
   VisitRow visit_row3;
   visit_row3.url_id = url_ids[1];
   visit_row3.visit_time = visit_times[2];
   visit_row3.is_indexed = true;
   visit_row3.transition = PageTransition::TYPED;
-  main_db_->AddVisit(&visit_row3);
+  main_db_->AddVisit(&visit_row3, SOURCE_BROWSED);
 
   VisitRow visit_row4;
   visit_row4.url_id = url_ids[2];
   visit_row4.visit_time = visit_times[3];
   visit_row4.is_indexed = true;
-  main_db_->AddVisit(&visit_row4);
+  main_db_->AddVisit(&visit_row4, SOURCE_BROWSED);
 
   // Full text index for each visit.
   text_db_->AddPageData(url_row1.url(), visit_row1.url_id, visit_row1.visit_id,
@@ -260,6 +269,35 @@ void ExpireHistoryTest::AddExampleData(URLID url_ids[3], Time visit_times[4]) {
                         UTF8ToUTF16("goats body"));
 }
 
+void ExpireHistoryTest::AddExampleSourceData(const GURL& url, URLID* id) {
+  if (!main_db_.get())
+    return;
+
+  Time last_visit_time = Time::Now();
+  // Add one URL.
+  URLRow url_row1(url);
+  url_row1.set_last_visit(last_visit_time);
+  url_row1.set_visit_count(4);
+  URLID url_id = main_db_->AddURL(url_row1);
+  *id = url_id;
+
+  // Four times for each visit.
+  VisitRow visit_row1(url_id, last_visit_time - TimeDelta::FromDays(4), 0,
+                      PageTransition::TYPED, 0);
+  main_db_->AddVisit(&visit_row1, SOURCE_SYNCED);
+
+  VisitRow visit_row2(url_id, last_visit_time - TimeDelta::FromDays(3), 0,
+                      PageTransition::TYPED, 0);
+  main_db_->AddVisit(&visit_row2, SOURCE_BROWSED);
+
+  VisitRow visit_row3(url_id, last_visit_time - TimeDelta::FromDays(2), 0,
+                      PageTransition::TYPED, 0);
+  main_db_->AddVisit(&visit_row3, SOURCE_EXTENSION);
+
+  VisitRow visit_row4(url_id, last_visit_time, 0, PageTransition::TYPED, 0);
+  main_db_->AddVisit(&visit_row4, SOURCE_FIREFOX_IMPORTED);
+}
+
 bool ExpireHistoryTest::HasFavIcon(FavIconID favicon_id) {
   if (!thumb_db_.get())
     return false;
@@ -271,8 +309,12 @@ bool ExpireHistoryTest::HasFavIcon(FavIconID favicon_id) {
 }
 
 bool ExpireHistoryTest::HasThumbnail(URLID url_id) {
-  std::vector<unsigned char> temp_data;
-  return thumb_db_->GetPageThumbnail(url_id, &temp_data);
+  URLRow info;
+  if (!main_db_->GetURLRow(url_id, &info))
+    return false;
+  GURL url = info.url();
+  RefCountedBytes *data;
+  return top_sites_->GetPageThumbnail(url, &data);
 }
 
 int ExpireHistoryTest::CountTextMatchesForURL(const GURL& url) {
@@ -507,7 +549,7 @@ TEST_F(ExpireHistoryTest, DontDeleteStarredURL) {
   ASSERT_TRUE(HasThumbnail(url_row.id()));
 
   // Unstar the URL and delete again.
-  bookmark_model_.SetURLStarred(url, std::wstring(), false);
+  bookmark_model_.SetURLStarred(url, string16(), false);
   expirer_.DeleteURL(url);
 
   // Now it should be completely deleted.
@@ -804,8 +846,52 @@ TEST_F(ExpireHistoryTest, ExpiringVisitsReader) {
   EXPECT_EQ(1U, visits.size());
 }
 
+// Tests how ArchiveSomeOldHistory treats source information.
+TEST_F(ExpireHistoryTest, ArchiveSomeOldHistoryWithSource) {
+  const GURL url("www.testsource.com");
+  URLID url_id;
+  AddExampleSourceData(url, &url_id);
+  const ExpiringVisitsReader* reader = expirer_.GetAllVisitsReader();
+
+  // Archiving all the visits we added.
+  ASSERT_FALSE(expirer_.ArchiveSomeOldHistory(Time::Now(), reader, 10));
+
+  URLRow archived_row;
+  ASSERT_TRUE(archived_db_->GetRowForURL(url, &archived_row));
+  VisitVector archived_visits;
+  archived_db_->GetVisitsForURL(archived_row.id(), &archived_visits);
+  ASSERT_EQ(4U, archived_visits.size());
+  VisitSourceMap sources;
+  archived_db_->GetVisitsSource(archived_visits, &sources);
+  ASSERT_EQ(3U, sources.size());
+  int result = 0;
+  VisitSourceMap::iterator iter;
+  for (int i = 0; i < 4; i++) {
+    iter = sources.find(archived_visits[i].visit_id);
+    if (iter == sources.end())
+      continue;
+    switch (iter->second) {
+      case history::SOURCE_EXTENSION:
+        result |= 0x1;
+        break;
+      case history::SOURCE_FIREFOX_IMPORTED:
+        result |= 0x2;
+        break;
+      case history::SOURCE_SYNCED:
+        result |= 0x4;
+      default:
+        break;
+    }
+  }
+  EXPECT_EQ(0x7, result);
+  main_db_->GetVisitsSource(archived_visits, &sources);
+  EXPECT_EQ(0U, sources.size());
+  main_db_->GetVisitsForURL(url_id, &archived_visits);
+  EXPECT_EQ(0U, archived_visits.size());
+}
+
 // TODO(brettw) add some visits with no URL to make sure everything is updated
-// properly. Have the visits also refer to nonexistant FTS rows.
+// properly. Have the visits also refer to nonexistent FTS rows.
 //
 // Maybe also refer to invalid favicons.
 
diff --git a/chrome/browser/history/history.cc b/chrome/browser/history/history.cc
index 0b92b6f..d70fd85 100644
--- a/chrome/browser/history/history.cc
+++ b/chrome/browser/history/history.cc
@@ -24,18 +24,18 @@
 
 #include "chrome/browser/history/history.h"
 
-#include "app/l10n_util.h"
 #include "base/callback.h"
 #include "base/message_loop.h"
 #include "base/path_service.h"
 #include "base/ref_counted.h"
+#include "base/string_util.h"
 #include "base/task.h"
 #include "chrome/browser/autocomplete/history_url_provider.h"
 #include "chrome/browser/browser_list.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/browser_window.h"
 #include "chrome/browser/chrome_thread.h"
-#include "chrome/browser/history/download_types.h"
+#include "chrome/browser/history/download_create_info.h"
 #include "chrome/browser/history/history_backend.h"
 #include "chrome/browser/history/history_notifications.h"
 #include "chrome/browser/history/history_types.h"
@@ -222,6 +222,16 @@ history::URLDatabase* HistoryService::InMemoryDatabase() {
   return NULL;
 }
 
+history::InMemoryURLIndex* HistoryService::InMemoryIndex() {
+  // NOTE: See comments in BackendLoaded() as to why we call
+  // LoadBackendIfNecessary() here even though it won't affect the return value
+  // for this call.
+  LoadBackendIfNecessary();
+  if (in_memory_backend_.get())
+    return in_memory_backend_->index();
+  return NULL;
+}
+
 void HistoryService::SetSegmentPresentationIndex(int64 segment_id, int index) {
   ScheduleAndForget(PRIORITY_UI,
                     &HistoryBackend::SetSegmentPresentationIndex,
@@ -229,7 +239,7 @@ void HistoryService::SetSegmentPresentationIndex(int64 segment_id, int index) {
 }
 
 void HistoryService::SetKeywordSearchTermsForURL(const GURL& url,
-                                                 TemplateURL::IDType keyword_id,
+                                                 TemplateURLID keyword_id,
                                                  const string16& term) {
   ScheduleAndForget(PRIORITY_UI,
                     &HistoryBackend::SetKeywordSearchTermsForURL,
@@ -237,14 +247,14 @@ void HistoryService::SetKeywordSearchTermsForURL(const GURL& url,
 }
 
 void HistoryService::DeleteAllSearchTermsForKeyword(
-    TemplateURL::IDType keyword_id) {
+    TemplateURLID keyword_id) {
   ScheduleAndForget(PRIORITY_UI,
                     &HistoryBackend::DeleteAllSearchTermsForKeyword,
                     keyword_id);
 }
 
 HistoryService::Handle HistoryService::GetMostRecentKeywordSearchTerms(
-    TemplateURL::IDType keyword_id,
+    TemplateURLID keyword_id,
     const string16& prefix,
     int max_count,
     CancelableRequestConsumerBase* consumer,
@@ -291,9 +301,10 @@ void HistoryService::AddPage(const GURL& url,
                              const GURL& referrer,
                              PageTransition::Type transition,
                              const history::RedirectList& redirects,
+                             history::VisitSource visit_source,
                              bool did_replace_entry) {
   AddPage(url, Time::Now(), id_scope, page_id, referrer, transition, redirects,
-          did_replace_entry);
+          visit_source, did_replace_entry);
 }
 
 void HistoryService::AddPage(const GURL& url,
@@ -303,37 +314,45 @@ void HistoryService::AddPage(const GURL& url,
                              const GURL& referrer,
                              PageTransition::Type transition,
                              const history::RedirectList& redirects,
+                             history::VisitSource visit_source,
                              bool did_replace_entry) {
+  scoped_refptr<history::HistoryAddPageArgs> request(
+      new history::HistoryAddPageArgs(url, time, id_scope, page_id, referrer,
+                                      redirects, transition, visit_source,
+                                      did_replace_entry));
+  AddPage(*request);
+}
+
+void HistoryService::AddPage(const history::HistoryAddPageArgs& add_page_args) {
   DCHECK(thread_) << "History service being called after cleanup";
 
   // Filter out unwanted URLs. We don't add auto-subframe URLs. They are a
   // large part of history (think iframes for ads) and we never display them in
   // history UI. We will still add manual subframes, which are ones the user
   // has clicked on to get.
-  if (!CanAddURL(url))
+  if (!CanAddURL(add_page_args.url))
     return;
 
   // Add link & all redirects to visited link list.
   VisitedLinkMaster* visited_links;
   if (profile_ && (visited_links = profile_->GetVisitedLinkMaster())) {
-    visited_links->AddURL(url);
+    visited_links->AddURL(add_page_args.url);
 
-    if (!redirects.empty()) {
+    if (!add_page_args.redirects.empty()) {
       // We should not be asked to add a page in the middle of a redirect chain.
-      DCHECK(redirects[redirects.size() - 1] == url);
+      DCHECK_EQ(add_page_args.url,
+                add_page_args.redirects[add_page_args.redirects.size() - 1]);
 
       // We need the !redirects.empty() condition above since size_t is unsigned
       // and will wrap around when we subtract one from a 0 size.
-      for (size_t i = 0; i < redirects.size() - 1; i++)
-        visited_links->AddURL(redirects[i]);
+      for (size_t i = 0; i < add_page_args.redirects.size() - 1; i++)
+        visited_links->AddURL(add_page_args.redirects[i]);
     }
   }
 
-  scoped_refptr<history::HistoryAddPageArgs> request(
-      new history::HistoryAddPageArgs(url, time, id_scope, page_id,
-                                      referrer, redirects, transition,
-                                      did_replace_entry));
-  ScheduleAndForget(PRIORITY_NORMAL, &HistoryBackend::AddPage, request);
+  ScheduleAndForget(PRIORITY_NORMAL, &HistoryBackend::AddPage,
+                    scoped_refptr<history::HistoryAddPageArgs>(
+                        add_page_args.Clone()));
 }
 
 void HistoryService::SetPageTitle(const GURL& url,
@@ -346,7 +365,8 @@ void HistoryService::AddPageWithDetails(const GURL& url,
                                         int visit_count,
                                         int typed_count,
                                         Time last_visit,
-                                        bool hidden) {
+                                        bool hidden,
+                                        history::VisitSource visit_source) {
   // Filter out unwanted URLs.
   if (!CanAddURL(url))
     return;
@@ -367,11 +387,12 @@ void HistoryService::AddPageWithDetails(const GURL& url,
   rows.push_back(row);
 
   ScheduleAndForget(PRIORITY_NORMAL,
-                    &HistoryBackend::AddPagesWithDetails, rows);
+                    &HistoryBackend::AddPagesWithDetails, rows, visit_source);
 }
 
 void HistoryService::AddPagesWithDetails(
-    const std::vector<history::URLRow>& info) {
+    const std::vector<history::URLRow>& info,
+    history::VisitSource visit_source) {
 
   // Add to the visited links system.
   VisitedLinkMaster* visited_links;
@@ -387,7 +408,7 @@ void HistoryService::AddPagesWithDetails(
   }
 
   ScheduleAndForget(PRIORITY_NORMAL,
-                    &HistoryBackend::AddPagesWithDetails, info);
+                    &HistoryBackend::AddPagesWithDetails, info, visit_source);
 }
 
 void HistoryService::SetPageContents(const GURL& url,
@@ -529,14 +550,6 @@ void HistoryService::RemoveDownloadsBetween(Time remove_begin,
                     remove_end);
 }
 
-HistoryService::Handle HistoryService::SearchDownloads(
-    const string16& search_text,
-    CancelableRequestConsumerBase* consumer,
-    DownloadSearchCallback* callback) {
-  return Schedule(PRIORITY_NORMAL, &HistoryBackend::SearchDownloads, consumer,
-                  new history::DownloadSearchRequest(callback), search_text);
-}
-
 HistoryService::Handle HistoryService::QueryHistory(
     const string16& text_query,
     const history::QueryOptions& options,
@@ -744,7 +757,6 @@ void HistoryService::LoadBackendIfNecessary() {
 }
 
 void HistoryService::OnDBLoaded() {
-  LOG(INFO) << "History backend finished loading";
   backend_loaded_ = true;
   NotificationService::current()->Notify(NotificationType::HISTORY_LOADED,
                                          Source<Profile>(profile_),
diff --git a/chrome/browser/history/history.h b/chrome/browser/history/history.h
index 9548f65..3d24981 100644
--- a/chrome/browser/history/history.h
+++ b/chrome/browser/history/history.h
@@ -4,8 +4,8 @@
 
 #ifndef CHROME_BROWSER_HISTORY_HISTORY_H_
 #define CHROME_BROWSER_HISTORY_HISTORY_H_
+#pragma once
 
-#include <string>
 #include <vector>
 
 #include "base/basictypes.h"
@@ -18,7 +18,7 @@
 #include "chrome/browser/cancelable_request.h"
 #include "chrome/browser/favicon_service.h"
 #include "chrome/browser/history/history_types.h"
-#include "chrome/browser/search_engines/template_url.h"
+#include "chrome/browser/search_engines/template_url_id.h"
 #include "chrome/common/notification_registrar.h"
 #include "chrome/common/page_transition_types.h"
 #include "chrome/common/ref_counted_util.h"
@@ -48,14 +48,14 @@ class TypedUrlDataTypeController;
 }
 
 namespace history {
-
 class InMemoryHistoryBackend;
+class InMemoryURLIndex;
+class HistoryAddPageArgs;
 class HistoryBackend;
 class HistoryDatabase;
 struct HistoryDetails;
 class HistoryQueryTest;
 class URLDatabase;
-
 }  // namespace history
 
 
@@ -150,6 +150,8 @@ class HistoryService : public CancelableRequestProvider,
   // TODO(brettw) this should return the InMemoryHistoryBackend.
   history::URLDatabase* InMemoryDatabase();
 
+  history::InMemoryURLIndex* InMemoryIndex();
+
   // Navigation ----------------------------------------------------------------
 
   // Adds the given canonical URL to history with the current time as the visit
@@ -182,6 +184,7 @@ class HistoryService : public CancelableRequestProvider,
                const GURL& referrer,
                PageTransition::Type transition,
                const history::RedirectList& redirects,
+               history::VisitSource visit_source,
                bool did_replace_entry);
 
   // For adding pages to history with a specific time. This is for testing
@@ -193,14 +196,18 @@ class HistoryService : public CancelableRequestProvider,
                const GURL& referrer,
                PageTransition::Type transition,
                const history::RedirectList& redirects,
+               history::VisitSource visit_source,
                bool did_replace_entry);
 
   // For adding pages to history where no tracking information can be done.
-  void AddPage(const GURL& url) {
-    AddPage(url, NULL, 0, GURL(), PageTransition::LINK, history::RedirectList(),
-            false);
+  void AddPage(const GURL& url, history::VisitSource visit_source) {
+    AddPage(url, NULL, 0, GURL(), PageTransition::LINK,
+            history::RedirectList(), visit_source, false);
   }
 
+  // All AddPage variants end up here.
+  void AddPage(const history::HistoryAddPageArgs& add_page_args);
+
   // Sets the title for the given page. The page should be in history. If it
   // is not, this operation is ignored. This call will not update the full
   // text index. The last title set when the page is indexed will be the
@@ -442,15 +449,6 @@ class HistoryService : public CancelableRequestProvider,
   // both directions.
   void RemoveDownloadsBetween(base::Time remove_begin, base::Time remove_end);
 
-  // Implemented by the caller of 'SearchDownloads' below, and is called when
-  // the history system has retrieved the search results.
-  typedef Callback2<Handle, std::vector<int64>*>::Type DownloadSearchCallback;
-
-  // Search for downloads that match the search text.
-  Handle SearchDownloads(const string16& search_text,
-                         CancelableRequestConsumerBase* consumer,
-                         DownloadSearchCallback* callback);
-
   // Visit Segments ------------------------------------------------------------
 
   typedef Callback2<Handle, std::vector<PageUsageData*>*>::Type
@@ -482,11 +480,11 @@ class HistoryService : public CancelableRequestProvider,
   // Sets the search terms for the specified url and keyword. url_id gives the
   // id of the url, keyword_id the id of the keyword and term the search term.
   void SetKeywordSearchTermsForURL(const GURL& url,
-                                   TemplateURL::IDType keyword_id,
+                                   TemplateURLID keyword_id,
                                    const string16& term);
 
   // Deletes all search terms for the specified keyword.
-  void DeleteAllSearchTermsForKeyword(TemplateURL::IDType keyword_id);
+  void DeleteAllSearchTermsForKeyword(TemplateURLID keyword_id);
 
   typedef Callback2<Handle, std::vector<history::KeywordSearchTermVisit>*>::Type
       GetMostRecentKeywordSearchTermsCallback;
@@ -496,7 +494,7 @@ class HistoryService : public CancelableRequestProvider,
   // in descending order up to |max_count| with the most recent search term
   // first.
   Handle GetMostRecentKeywordSearchTerms(
-      TemplateURL::IDType keyword_id,
+      TemplateURLID keyword_id,
       const string16& prefix,
       int max_count,
       CancelableRequestConsumerBase* consumer,
@@ -541,10 +539,12 @@ class HistoryService : public CancelableRequestProvider,
                           int visit_count,
                           int typed_count,
                           base::Time last_visit,
-                          bool hidden);
+                          bool hidden,
+                          history::VisitSource visit_source);
 
   // The same as AddPageWithDetails() but takes a vector.
-  void AddPagesWithDetails(const std::vector<history::URLRow>& info);
+  void AddPagesWithDetails(const std::vector<history::URLRow>& info,
+                           history::VisitSource visit_source);
 
   // Starts the TopSites migration in the HistoryThread. Called by the
   // BackendDelegate.
diff --git a/chrome/browser/history/history_backend.cc b/chrome/browser/history/history_backend.cc
index 0f512db..237b14b 100644
--- a/chrome/browser/history/history_backend.cc
+++ b/chrome/browser/history/history_backend.cc
@@ -17,11 +17,12 @@
 #include "base/time.h"
 #include "chrome/browser/autocomplete/history_url_provider.h"
 #include "chrome/browser/bookmarks/bookmark_service.h"
-#include "chrome/browser/history/download_types.h"
+#include "chrome/browser/history/download_create_info.h"
 #include "chrome/browser/history/history_notifications.h"
 #include "chrome/browser/history/history_publisher.h"
 #include "chrome/browser/history/in_memory_history_backend.h"
 #include "chrome/browser/history/page_usage_data.h"
+#include "chrome/browser/history/top_sites.h"
 #include "chrome/common/chrome_constants.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/notification_type.h"
@@ -362,8 +363,6 @@ SegmentID HistoryBackend::UpdateSegments(const GURL& url,
 }
 
 void HistoryBackend::AddPage(scoped_refptr<HistoryAddPageArgs> request) {
-  DLOG(INFO) << "Adding page " << request->url.possibly_invalid_spec();
-
   if (!db_.get())
     return;
 
@@ -405,7 +404,7 @@ void HistoryBackend::AddPage(scoped_refptr<HistoryAddPageArgs> request) {
 
     // No redirect case (one element means just the page itself).
     last_ids = AddPageVisit(request->url, last_recorded_time_,
-                            last_ids.second, t);
+                            last_ids.second, t, request->visit_source);
 
     // Update the segment for this visit. KEYWORD_GENERATED visits should not
     // result in changing most visited, so we don't update segments (most
@@ -471,7 +470,8 @@ void HistoryBackend::AddPage(scoped_refptr<HistoryAddPageArgs> request) {
       // them anyway, and if we ever decide to, we can reconstruct their order
       // from the redirect chain.
       last_ids = AddPageVisit(request->redirects[redirect_index],
-                              last_recorded_time_, last_ids.second, t);
+                              last_recorded_time_, last_ids.second,
+                              t, request->visit_source);
       if (t & PageTransition::CHAIN_START) {
         // Update the segment for this visit.
         UpdateSegments(request->redirects[redirect_index],
@@ -548,7 +548,7 @@ void HistoryBackend::InitImpl() {
   // Fill the in-memory database and send it back to the history service on the
   // main thread.
   InMemoryHistoryBackend* mem_backend = new InMemoryHistoryBackend;
-  if (mem_backend->Init(history_name))
+  if (mem_backend->Init(history_name, db_.get()))
     delegate_->SetInMemoryBackend(mem_backend);  // Takes ownership of pointer.
   else
     delete mem_backend;  // Error case, run without the in-memory DB.
@@ -581,11 +581,12 @@ void HistoryBackend::InitImpl() {
 
   // Thumbnail database.
   thumbnail_db_.reset(new ThumbnailDatabase());
-  if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kTopSites)) {
-    if (!db_->needs_version_18_migration()) {
-      // No convertion needed - use new filename right away.
-      thumbnail_name = GetFaviconsFileName();
-    }
+  if (history::TopSites::IsEnabled()) {
+    // TODO(sky): once we reenable top sites this needs to be fixed.
+    // if (!db_->needs_version_18_migration()) {
+    // No convertion needed - use new filename right away.
+    // thumbnail_name = GetFaviconsFileName();
+    // }
   }
   if (thumbnail_db_->Init(thumbnail_name,
                           history_publisher_.get()) != sql::INIT_OK) {
@@ -598,11 +599,12 @@ void HistoryBackend::InitImpl() {
     thumbnail_db_.reset();
   }
 
-  if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kTopSites)) {
-    if (db_->needs_version_18_migration()) {
-      LOG(INFO) << "Starting TopSites migration";
-      delegate_->StartTopSitesMigration();
-    }
+  if (history::TopSites::IsEnabled()) {
+    // TODO(sky): fix when reenabling top sites migration.
+    // if (db_->needs_version_18_migration()) {
+    // LOG(INFO) << "Starting TopSites migration";
+    // delegate_->StartTopSitesMigration();
+    // }
   }
 
   // Archived database.
@@ -651,7 +653,8 @@ std::pair<URLID, VisitID> HistoryBackend::AddPageVisit(
     const GURL& url,
     Time time,
     VisitID referring_visit,
-    PageTransition::Type transition) {
+    PageTransition::Type transition,
+    VisitSource visit_source) {
   // Top-level frame navigations are visible, everything else is hidden
   bool new_hidden = !PageTransition::IsMainFrame(transition);
 
@@ -708,7 +711,7 @@ std::pair<URLID, VisitID> HistoryBackend::AddPageVisit(
 
   // Add the visit with the time to the database.
   VisitRow visit_info(url_id, time, referring_visit, transition, 0);
-  VisitID visit_id = db_->AddVisit(&visit_info);
+  VisitID visit_id = db_->AddVisit(&visit_info, visit_source);
 
   if (visit_info.visit_time < first_recorded_time_)
     first_recorded_time_ = visit_info.visit_time;
@@ -727,7 +730,8 @@ std::pair<URLID, VisitID> HistoryBackend::AddPageVisit(
   return std::make_pair(url_id, visit_id);
 }
 
-void HistoryBackend::AddPagesWithDetails(const std::vector<URLRow>& urls) {
+void HistoryBackend::AddPagesWithDetails(const std::vector<URLRow>& urls,
+                                         VisitSource visit_source) {
   if (!db_.get())
     return;
 
@@ -789,7 +793,7 @@ void HistoryBackend::AddPagesWithDetails(const std::vector<URLRow>& urls) {
         PageTransition::LINK | PageTransition::CHAIN_START |
         PageTransition::CHAIN_END, 0);
     visit_info.is_indexed = has_indexed;
-    if (!visit_database->AddVisit(&visit_info)) {
+    if (!visit_database->AddVisit(&visit_info, visit_source)) {
       NOTREACHED() << "Adding visit failed.";
       return;
     }
@@ -906,11 +910,12 @@ bool HistoryBackend::UpdateURL(URLID id, const history::URLRow& url) {
 }
 
 bool HistoryBackend::AddVisits(const GURL& url,
-                               const std::vector<base::Time>& visits) {
+                               const std::vector<base::Time>& visits,
+                               VisitSource visit_source) {
   if (db_.get()) {
     for (std::vector<base::Time>::const_iterator visit = visits.begin();
          visit != visits.end(); ++visit) {
-      if (!AddPageVisit(url, *visit, 0, 0).first) {
+      if (!AddPageVisit(url, *visit, 0, 0, visit_source).first) {
         return false;
       }
     }
@@ -1022,7 +1027,7 @@ void HistoryBackend::QuerySegmentUsage(
 // Keyword visits --------------------------------------------------------------
 
 void HistoryBackend::SetKeywordSearchTermsForURL(const GURL& url,
-                                                 TemplateURL::IDType keyword_id,
+                                                 TemplateURLID keyword_id,
                                                  const string16& term) {
   if (!db_.get())
     return;
@@ -1040,7 +1045,7 @@ void HistoryBackend::SetKeywordSearchTermsForURL(const GURL& url,
 }
 
 void HistoryBackend::DeleteAllSearchTermsForKeyword(
-    TemplateURL::IDType keyword_id) {
+    TemplateURLID keyword_id) {
   if (!db_.get())
     return;
 
@@ -1051,7 +1056,7 @@ void HistoryBackend::DeleteAllSearchTermsForKeyword(
 
 void HistoryBackend::GetMostRecentKeywordSearchTerms(
     scoped_refptr<GetMostRecentKeywordSearchTermsRequest> request,
-    TemplateURL::IDType keyword_id,
+    TemplateURLID keyword_id,
     const string16& prefix,
     int max_count) {
   if (request->canceled())
@@ -1126,17 +1131,6 @@ void HistoryBackend::RemoveDownloadsBetween(const Time remove_begin,
     db_->RemoveDownloadsBetween(remove_begin, remove_end);
 }
 
-void HistoryBackend::SearchDownloads(
-    scoped_refptr<DownloadSearchRequest> request,
-    const string16& search_text) {
-  if (request->canceled())
-    return;
-  if (db_.get())
-    db_->SearchDownloads(&request->value, search_text);
-  request->ForwardResult(DownloadSearchRequest::TupleType(request->handle(),
-                                                          &request->value));
-}
-
 void HistoryBackend::QueryHistory(scoped_refptr<QueryHistoryRequest> request,
                                   const string16& text_query,
                                   const QueryOptions& options) {
@@ -2156,9 +2150,16 @@ BookmarkService* HistoryBackend::GetBookmarkService() {
 }
 
 void HistoryBackend::MigrateThumbnailsDatabase() {
-  thumbnail_db_->RenameAndDropThumbnails(GetThumbnailFileName(),
-                                         GetFaviconsFileName());
-  db_->MigrationToTopSitesDone();
+  // If there is no History DB, we can't record that the migration was done.
+  // It will be recorded on the next run.
+  if (db_.get()) {
+    // If there is no thumbnail DB, we can still record a successful migration.
+    if (thumbnail_db_.get()) {
+      thumbnail_db_->RenameAndDropThumbnails(GetThumbnailFileName(),
+                                             GetFaviconsFileName());
+    }
+    db_->MigrationToTopSitesDone();
+  }
 }
 
 }  // namespace history
diff --git a/chrome/browser/history/history_backend.h b/chrome/browser/history/history_backend.h
index cbda2e9..f3e76cf 100644
--- a/chrome/browser/history/history_backend.h
+++ b/chrome/browser/history/history_backend.h
@@ -4,6 +4,7 @@
 
 #ifndef CHROME_BROWSER_HISTORY_HISTORY_BACKEND_H_
 #define CHROME_BROWSER_HISTORY_HISTORY_BACKEND_H_
+#pragma once
 
 #include <utility>
 
@@ -11,7 +12,6 @@
 #include "base/gtest_prod_util.h"
 #include "base/scoped_ptr.h"
 #include "chrome/browser/history/archived_database.h"
-#include "chrome/browser/history/download_types.h"
 #include "chrome/browser/history/expire_history_backend.h"
 #include "chrome/browser/history/history_database.h"
 #include "chrome/browser/history/history_marshaling.h"
@@ -19,9 +19,11 @@
 #include "chrome/browser/history/text_database_manager.h"
 #include "chrome/browser/history/thumbnail_database.h"
 #include "chrome/browser/history/visit_tracker.h"
+#include "chrome/browser/search_engines/template_url_id.h"
 #include "chrome/common/mru_cache.h"
 
 class BookmarkService;
+struct DownloadCreateInfo;
 class TestingProfile;
 struct ThumbnailScore;
 
@@ -224,8 +226,6 @@ class HistoryBackend : public base::RefCountedThreadSafe<HistoryBackend>,
   void RemoveDownloadsBetween(const base::Time remove_begin,
                               const base::Time remove_end);
   void RemoveDownloads(const base::Time remove_end);
-  void SearchDownloads(scoped_refptr<DownloadSearchRequest>,
-                       const string16& search_text);
 
   // Segment usage -------------------------------------------------------------
 
@@ -238,14 +238,14 @@ class HistoryBackend : public base::RefCountedThreadSafe<HistoryBackend>,
   // Keyword search terms ------------------------------------------------------
 
   void SetKeywordSearchTermsForURL(const GURL& url,
-                                   TemplateURL::IDType keyword_id,
+                                   TemplateURLID keyword_id,
                                    const string16& term);
 
-  void DeleteAllSearchTermsForKeyword(TemplateURL::IDType keyword_id);
+  void DeleteAllSearchTermsForKeyword(TemplateURLID keyword_id);
 
   void GetMostRecentKeywordSearchTerms(
       scoped_refptr<GetMostRecentKeywordSearchTermsRequest> request,
-      TemplateURL::IDType keyword_id,
+      TemplateURLID keyword_id,
       const string16& prefix,
       int max_count);
 
@@ -259,8 +259,10 @@ class HistoryBackend : public base::RefCountedThreadSafe<HistoryBackend>,
 
   virtual bool UpdateURL(URLID id, const history::URLRow& url);
 
+  // While adding visits in batch, the source needs to be provided.
   virtual bool AddVisits(const GURL& url,
-                         const std::vector<base::Time>& visits);
+                         const std::vector<base::Time>& visits,
+                         VisitSource visit_source);
 
   virtual bool RemoveVisits(const VisitVector& visits);
 
@@ -293,7 +295,9 @@ class HistoryBackend : public base::RefCountedThreadSafe<HistoryBackend>,
 
   // Adds the given rows to the database if it doesn't exist. A visit will be
   // added for each given URL at the last visit time in the URLRow.
-  void AddPagesWithDetails(const std::vector<URLRow>& info);
+  // Each visit will have the visit_source type set.
+  void AddPagesWithDetails(const std::vector<URLRow>& info,
+                           VisitSource visit_source);
 
 #if defined(UNIT_TEST)
   HistoryDatabase* db() const { return db_.get(); }
@@ -313,6 +317,11 @@ class HistoryBackend : public base::RefCountedThreadSafe<HistoryBackend>,
   FRIEND_TEST_ALL_PREFIXES(HistoryBackendTest, URLsNoLongerBookmarked);
   FRIEND_TEST_ALL_PREFIXES(HistoryBackendTest, StripUsernamePasswordTest);
   FRIEND_TEST_ALL_PREFIXES(HistoryBackendTest, DeleteThumbnailsDatabaseTest);
+  FRIEND_TEST_ALL_PREFIXES(HistoryBackendTest, AddPageVisitSource);
+  FRIEND_TEST_ALL_PREFIXES(HistoryBackendTest, AddPageArgsSource);
+  FRIEND_TEST_ALL_PREFIXES(HistoryBackendTest, AddVisitsSource);
+  FRIEND_TEST_ALL_PREFIXES(HistoryBackendTest, RemoveVisitsSource);
+  FRIEND_TEST_ALL_PREFIXES(HistoryBackendTest, MigrationVisitSource);
   friend class ::TestingProfile;
 
   // Computes the name of the specified database on disk.
@@ -340,7 +349,8 @@ class HistoryBackend : public base::RefCountedThreadSafe<HistoryBackend>,
   std::pair<URLID, VisitID> AddPageVisit(const GURL& url,
                                          base::Time time,
                                          VisitID referring_visit,
-                                         PageTransition::Type transition);
+                                         PageTransition::Type transition,
+                                         VisitSource visit_source);
 
   // Returns a redirect chain in |redirects| for the VisitID
   // |cur_visit|. |cur_visit| is assumed to be valid. Assumes that
diff --git a/chrome/browser/history/history_backend_unittest.cc b/chrome/browser/history/history_backend_unittest.cc
index 24cc1cd..907b7b6 100644
--- a/chrome/browser/history/history_backend_unittest.cc
+++ b/chrome/browser/history/history_backend_unittest.cc
@@ -4,15 +4,21 @@
 
 #include "base/file_path.h"
 #include "base/file_util.h"
+#include "base/command_line.h"
 #include "base/path_service.h"
 #include "base/ref_counted.h"
 #include "base/scoped_ptr.h"
+#include "base/string16.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/bookmarks/bookmark_model.h"
 #include "chrome/browser/history/history_backend.h"
 #include "chrome/browser/history/history_notifications.h"
 #include "chrome/browser/history/in_memory_history_backend.h"
 #include "chrome/browser/history/in_memory_database.h"
+#include "chrome/browser/history/top_sites.h"
+#include "chrome/common/chrome_constants.h"
+#include "chrome/common/chrome_paths.h"
+#include "chrome/common/chrome_switches.h"
 #include "chrome/common/notification_service.h"
 #include "chrome/common/thumbnail_score.h"
 #include "chrome/tools/profiles/thumbnail-inl.h"
@@ -72,7 +78,7 @@ class HistoryBackendTest : public testing::Test {
     scoped_refptr<history::HistoryAddPageArgs> request(
         new history::HistoryAddPageArgs(
             redirects.back(), Time::Now(), scope, page_id, GURL(),
-            redirects, PageTransition::LINK, true));
+            redirects, PageTransition::LINK, history::SOURCE_BROWSED, true));
     backend_->AddPage(request);
   }
 
@@ -92,7 +98,8 @@ class HistoryBackendTest : public testing::Test {
       redirects.push_back(url2);
     scoped_refptr<HistoryAddPageArgs> request(
         new HistoryAddPageArgs(url2, base::Time(), dummy_scope, 0, url1,
-            redirects, PageTransition::CLIENT_REDIRECT, did_replace));
+            redirects, PageTransition::CLIENT_REDIRECT,
+            history::SOURCE_BROWSED, did_replace));
     backend_->AddPage(request);
 
     *transition1 = getTransition(url1);
@@ -109,6 +116,10 @@ class HistoryBackendTest : public testing::Test {
     return visits[0].transition;
   }
 
+  FilePath getTestDir() {
+    return test_dir_;
+  }
+
   BookmarkModel bookmark_model_;
 
  protected:
@@ -212,7 +223,7 @@ TEST_F(HistoryBackendTest, DeleteAll) {
   std::vector<URLRow> rows;
   rows.push_back(row2);  // Reversed order for the same reason as favicons.
   rows.push_back(row1);
-  backend_->AddPagesWithDetails(rows);
+  backend_->AddPagesWithDetails(rows, history::SOURCE_BROWSED);
 
   URLID row1_id = backend_->db_->GetRowForURL(row1.url(), NULL);
   URLID row2_id = backend_->db_->GetRowForURL(row2.url(), NULL);
@@ -250,7 +261,7 @@ TEST_F(HistoryBackendTest, DeleteAll) {
 
   // Star row1.
   bookmark_model_.AddURL(
-      bookmark_model_.GetBookmarkBarNode(), 0, std::wstring(), row1.url());
+      bookmark_model_.GetBookmarkBarNode(), 0, string16(), row1.url());
 
   // Set full text index for each one.
   backend_->text_database_->AddPageData(row1.url(), row1_id, visit1_id,
@@ -342,14 +353,14 @@ TEST_F(HistoryBackendTest, URLsNoLongerBookmarked) {
   std::vector<URLRow> rows;
   rows.push_back(row2);  // Reversed order for the same reason as favicons.
   rows.push_back(row1);
-  backend_->AddPagesWithDetails(rows);
+  backend_->AddPagesWithDetails(rows, history::SOURCE_BROWSED);
 
   URLID row1_id = backend_->db_->GetRowForURL(row1.url(), NULL);
   URLID row2_id = backend_->db_->GetRowForURL(row2.url(), NULL);
 
   // Star the two URLs.
-  bookmark_model_.SetURLStarred(row1.url(), std::wstring(), true);
-  bookmark_model_.SetURLStarred(row2.url(), std::wstring(), true);
+  bookmark_model_.SetURLStarred(row1.url(), string16(), true);
+  bookmark_model_.SetURLStarred(row2.url(), string16(), true);
 
   // Delete url 2. Because url 2 is starred this won't delete the URL, only
   // the visits.
@@ -366,7 +377,7 @@ TEST_F(HistoryBackendTest, URLsNoLongerBookmarked) {
       backend_->thumbnail_db_->GetFavIconIDForFavIconURL(favicon_url2));
 
   // Unstar row2.
-  bookmark_model_.SetURLStarred(row2.url(), std::wstring(), false);
+  bookmark_model_.SetURLStarred(row2.url(), string16(), false);
   // Tell the backend it was unstarred. We have to explicitly do this as
   // BookmarkModel isn't wired up to the backend during testing.
   std::set<GURL> unstarred_urls;
@@ -380,7 +391,7 @@ TEST_F(HistoryBackendTest, URLsNoLongerBookmarked) {
       backend_->thumbnail_db_->GetFavIconIDForFavIconURL(favicon_url2));
 
   // Unstar row 1.
-  bookmark_model_.SetURLStarred(row1.url(), std::wstring(), false);
+  bookmark_model_.SetURLStarred(row1.url(), string16(), false);
   // Tell the backend it was unstarred. We have to explicitly do this as
   // BookmarkModel isn't wired up to the backend during testing.
   unstarred_urls.clear();
@@ -402,6 +413,8 @@ TEST_F(HistoryBackendTest, URLsNoLongerBookmarked) {
 
 TEST_F(HistoryBackendTest, GetPageThumbnailAfterRedirects) {
   ASSERT_TRUE(backend_.get());
+  if (history::TopSites::IsEnabled())
+    return;
 
   const char* base_url = "http://mail";
   const char* thumbnail_url = "http://mail.google.com";
@@ -448,7 +461,8 @@ TEST_F(HistoryBackendTest, KeywordGenerated) {
   scoped_refptr<HistoryAddPageArgs> request(
       new HistoryAddPageArgs(url, visit_time, NULL, 0, GURL(),
                              history::RedirectList(),
-                             PageTransition::KEYWORD_GENERATED, false));
+                             PageTransition::KEYWORD_GENERATED,
+                             history::SOURCE_BROWSED, false));
   backend_->AddPage(request);
 
   // A row should have been added for the url.
@@ -531,7 +545,7 @@ TEST_F(HistoryBackendTest, ImportedFaviconsTest) {
   std::vector<URLRow> rows;
   rows.push_back(row1);
   rows.push_back(row2);
-  backend_->AddPagesWithDetails(rows);
+  backend_->AddPagesWithDetails(rows, history::SOURCE_BROWSED);
   URLRow url_row1, url_row2;
   EXPECT_FALSE(backend_->db_->GetRowForURL(row1.url(), &url_row1) == 0);
   EXPECT_FALSE(backend_->db_->GetRowForURL(row2.url(), &url_row2) == 0);
@@ -568,8 +582,8 @@ TEST_F(HistoryBackendTest, ImportedFaviconsTest) {
   EXPECT_TRUE(backend_->db_->GetRowForURL(url3, &url_row3) == 0);
 
   // If the URL is bookmarked, it should get added to history with 0 visits.
-  bookmark_model_.AddURL(bookmark_model_.GetBookmarkBarNode(), 0,
-                         std::wstring(), url3);
+  bookmark_model_.AddURL(bookmark_model_.GetBookmarkBarNode(), 0, string16(),
+                         url3);
   backend_->SetImportedFavicons(favicons);
   EXPECT_FALSE(backend_->db_->GetRowForURL(url3, &url_row3) == 0);
   EXPECT_TRUE(url_row3.visit_count() == 0);
@@ -586,7 +600,8 @@ TEST_F(HistoryBackendTest, StripUsernamePasswordTest) {
 
   // Visit the url with username, password.
   backend_->AddPageVisit(url, base::Time::Now(), 0,
-    PageTransition::GetQualifier(PageTransition::TYPED));
+    PageTransition::GetQualifier(PageTransition::TYPED),
+    history::SOURCE_BROWSED);
 
   // Fetch the row information about stripped url from history db.
   VisitVector visits;
@@ -598,9 +613,222 @@ TEST_F(HistoryBackendTest, StripUsernamePasswordTest) {
 }
 
 TEST_F(HistoryBackendTest, DeleteThumbnailsDatabaseTest) {
+  if (history::TopSites::IsEnabled())
+    return;
+
   EXPECT_TRUE(backend_->thumbnail_db_->NeedsMigrationToTopSites());
   backend_->delegate_->StartTopSitesMigration();
   EXPECT_FALSE(backend_->thumbnail_db_->NeedsMigrationToTopSites());
 }
 
+TEST_F(HistoryBackendTest, AddPageVisitSource) {
+  ASSERT_TRUE(backend_.get());
+
+  GURL url("http://www.google.com");
+
+  // Clear all history.
+  backend_->DeleteAllHistory();
+
+  // Assume visiting the url from an externsion.
+  backend_->AddPageVisit(url, base::Time::Now(), 0, PageTransition::TYPED,
+                         history::SOURCE_EXTENSION);
+  // Assume the url is imported from Firefox.
+  backend_->AddPageVisit(url, base::Time::Now(), 0, PageTransition::TYPED,
+                         history::SOURCE_FIREFOX_IMPORTED);
+  // Assume this url is also synced.
+  backend_->AddPageVisit(url, base::Time::Now(), 0, PageTransition::TYPED,
+                         history::SOURCE_SYNCED);
+
+  // Fetch the row information about the url from history db.
+  VisitVector visits;
+  URLID row_id = backend_->db_->GetRowForURL(url, NULL);
+  backend_->db_->GetVisitsForURL(row_id, &visits);
+
+  // Check if all the visits to the url are stored in database.
+  ASSERT_EQ(3U, visits.size());
+  VisitSourceMap visit_sources;
+  backend_->db_->GetVisitsSource(visits, &visit_sources);
+  ASSERT_EQ(3U, visit_sources.size());
+  int sources = 0;
+  for (int i = 0; i < 3; i++) {
+    switch (visit_sources[visits[i].visit_id]) {
+      case history::SOURCE_EXTENSION:
+        sources |= 0x1;
+        break;
+      case history::SOURCE_FIREFOX_IMPORTED:
+        sources |= 0x2;
+        break;
+      case history::SOURCE_SYNCED:
+        sources |= 0x4;
+      default:
+        break;
+    }
+  }
+  EXPECT_EQ(0x7, sources);
+}
+
+TEST_F(HistoryBackendTest, AddPageArgsSource) {
+  ASSERT_TRUE(backend_.get());
+
+  GURL url("http://testpageargs.com");
+
+  // Assume this page is browsed by user.
+  scoped_refptr<HistoryAddPageArgs> request1(
+      new HistoryAddPageArgs(url, base::Time::Now(), NULL, 0, GURL(),
+                             history::RedirectList(),
+                             PageTransition::KEYWORD_GENERATED,
+                             history::SOURCE_BROWSED, false));
+  backend_->AddPage(request1);
+  // Assume this page is synced.
+  scoped_refptr<HistoryAddPageArgs> request2(
+      new HistoryAddPageArgs(url, base::Time::Now(), NULL, 0, GURL(),
+                             history::RedirectList(),
+                             PageTransition::LINK,
+                             history::SOURCE_SYNCED, false));
+  backend_->AddPage(request2);
+  // Assume this page is browsed again.
+  scoped_refptr<HistoryAddPageArgs> request3(
+      new HistoryAddPageArgs(url, base::Time::Now(), NULL, 0, GURL(),
+                             history::RedirectList(),
+                             PageTransition::TYPED,
+                             history::SOURCE_BROWSED, false));
+  backend_->AddPage(request3);
+
+  // Three visits should be added with proper sources.
+  VisitVector visits;
+  URLRow row;
+  URLID id = backend_->db()->GetRowForURL(url, &row);
+  ASSERT_TRUE(backend_->db()->GetVisitsForURL(id, &visits));
+  ASSERT_EQ(3U, visits.size());
+  VisitSourceMap visit_sources;
+  backend_->db_->GetVisitsSource(visits, &visit_sources);
+  ASSERT_EQ(1U, visit_sources.size());
+  EXPECT_EQ(history::SOURCE_SYNCED, visit_sources.begin()->second);
+}
+
+TEST_F(HistoryBackendTest, AddVisitsSource) {
+  ASSERT_TRUE(backend_.get());
+
+  GURL url1("http://www.cnn.com");
+  std::vector<base::Time> visits1;
+  visits1.push_back(Time::Now() - base::TimeDelta::FromDays(5));
+  visits1.push_back(Time::Now() - base::TimeDelta::FromDays(1));
+  visits1.push_back(Time::Now());
+
+  GURL url2("http://www.example.com");
+  std::vector<base::Time> visits2;
+  visits2.push_back(Time::Now() - base::TimeDelta::FromDays(10));
+  visits2.push_back(Time::Now());
+
+  // Clear all history.
+  backend_->DeleteAllHistory();
+
+  // Add the visits.
+  backend_->AddVisits(url1, visits1, history::SOURCE_IE_IMPORTED);
+  backend_->AddVisits(url2, visits2, history::SOURCE_SYNCED);
+
+  // Verify the visits were added with their sources.
+  VisitVector visits;
+  URLRow row;
+  URLID id = backend_->db()->GetRowForURL(url1, &row);
+  ASSERT_TRUE(backend_->db()->GetVisitsForURL(id, &visits));
+  ASSERT_EQ(3U, visits.size());
+  VisitSourceMap visit_sources;
+  backend_->db_->GetVisitsSource(visits, &visit_sources);
+  ASSERT_EQ(3U, visit_sources.size());
+  for (int i = 0; i < 3; i++)
+    EXPECT_EQ(history::SOURCE_IE_IMPORTED, visit_sources[visits[i].visit_id]);
+  id = backend_->db()->GetRowForURL(url2, &row);
+  ASSERT_TRUE(backend_->db()->GetVisitsForURL(id, &visits));
+  ASSERT_EQ(2U, visits.size());
+  backend_->db_->GetVisitsSource(visits, &visit_sources);
+  ASSERT_EQ(2U, visit_sources.size());
+  for (int i = 0; i < 2; i++)
+    EXPECT_EQ(history::SOURCE_SYNCED, visit_sources[visits[i].visit_id]);
+}
+
+TEST_F(HistoryBackendTest, RemoveVisitsSource) {
+  ASSERT_TRUE(backend_.get());
+
+  GURL url1("http://www.cnn.com");
+  std::vector<base::Time> visits1;
+  visits1.push_back(Time::Now() - base::TimeDelta::FromDays(5));
+  visits1.push_back(Time::Now());
+
+  GURL url2("http://www.example.com");
+  std::vector<base::Time> visits2;
+  visits2.push_back(Time::Now() - base::TimeDelta::FromDays(10));
+  visits2.push_back(Time::Now());
+
+  // Clear all history.
+  backend_->DeleteAllHistory();
+
+  // Add the visits.
+  backend_->AddVisits(url1, visits1, history::SOURCE_IE_IMPORTED);
+  backend_->AddVisits(url2, visits2, history::SOURCE_SYNCED);
+
+  // Verify the visits of url1 were added.
+  VisitVector visits;
+  URLRow row;
+  URLID id = backend_->db()->GetRowForURL(url1, &row);
+  ASSERT_TRUE(backend_->db()->GetVisitsForURL(id, &visits));
+  ASSERT_EQ(2U, visits.size());
+  // Remove these visits.
+  ASSERT_TRUE(backend_->RemoveVisits(visits));
+
+  // Now check only url2's source in visit_source table.
+  VisitSourceMap visit_sources;
+  backend_->db_->GetVisitsSource(visits, &visit_sources);
+  ASSERT_EQ(0U, visit_sources.size());
+  id = backend_->db()->GetRowForURL(url2, &row);
+  ASSERT_TRUE(backend_->db()->GetVisitsForURL(id, &visits));
+  ASSERT_EQ(2U, visits.size());
+  backend_->db_->GetVisitsSource(visits, &visit_sources);
+  ASSERT_EQ(2U, visit_sources.size());
+  for (int i = 0; i < 2; i++)
+    EXPECT_EQ(history::SOURCE_SYNCED, visit_sources[visits[i].visit_id]);
+}
+
+// Test for migration of adding visit_source table.
+TEST_F(HistoryBackendTest, MigrationVisitSource) {
+  ASSERT_TRUE(backend_.get());
+
+  FilePath old_history_path;
+  ASSERT_TRUE(PathService::Get(chrome::DIR_TEST_DATA, &old_history_path));
+  old_history_path = old_history_path.AppendASCII("History");
+  old_history_path = old_history_path.AppendASCII("HistoryNoSource");
+
+  // Copy history database file to current directory so that it will be deleted
+  // in Teardown.
+  FilePath new_history_path(getTestDir());
+  file_util::Delete(new_history_path, true);
+  file_util::CreateDirectory(new_history_path);
+  FilePath new_history_file = new_history_path.Append(chrome::kHistoryFilename);
+  ASSERT_TRUE(file_util::CopyFile(old_history_path, new_history_file));
+
+  backend_->Closing();
+  backend_ = new HistoryBackend(new_history_path,
+                                new HistoryBackendTestDelegate(this),
+                                &bookmark_model_);
+  backend_->Init(false);
+
+  // Now the database should already be migrated.
+  // Check version first.
+  int cur_version = HistoryDatabase::GetCurrentVersion();
+  sql::Connection db;
+  ASSERT_TRUE(db.Open(new_history_file));
+  sql::Statement s(db.GetUniqueStatement(
+      "SELECT value FROM meta WHERE key = 'version'"));
+  ASSERT_TRUE(s.Step());
+  int file_version = s.ColumnInt(0);
+  EXPECT_EQ(cur_version, file_version);
+
+  // Check visit_source table is created and empty.
+  s.Assign(db.GetUniqueStatement(
+      "SELECT name FROM sqlite_master WHERE name=\"visit_source\""));
+  ASSERT_TRUE(s.Step());
+  s.Assign(db.GetUniqueStatement("SELECT * FROM visit_source LIMIT 10"));
+  EXPECT_FALSE(s.Step());
+}
+
 }  // namespace history
diff --git a/chrome/browser/history/history_database.cc b/chrome/browser/history/history_database.cc
index 26bb81a..4661814 100644
--- a/chrome/browser/history/history_database.cc
+++ b/chrome/browser/history/history_database.cc
@@ -26,7 +26,7 @@ namespace {
 // Current version number. We write databases at the "current" version number,
 // but any previous version that can read the "compatible" one can make do with
 // or database without *too* many bad effects.
-static const int kCurrentVersionNumber = 18;
+static const int kCurrentVersionNumber = 19;
 static const int kCompatibleVersionNumber = 16;
 static const char kEarlyExpirationThresholdKey[] = "early_expiration_threshold";
 
@@ -56,8 +56,7 @@ void ComputeDatabaseMetrics(const FilePath& history_name,
 }  // namespace
 
 HistoryDatabase::HistoryDatabase()
-    : needs_version_17_migration_(false),
-      needs_version_18_migration_(false) {
+    : needs_version_17_migration_(false) {
 }
 
 HistoryDatabase::~HistoryDatabase() {
@@ -134,14 +133,7 @@ void HistoryDatabase::BeginExclusiveMode() {
 
 // static
 int HistoryDatabase::GetCurrentVersion() {
-  // Temporary solution while TopSites is behind a flag. If there is
-  // no flag, we are still using the Thumbnails file, i.e. we are at
-  // version 17.
-  if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kTopSites)) {
-    return kCurrentVersionNumber;
-  } else {
-    return kCurrentVersionNumber - 1;
-  }
+  return kCurrentVersionNumber;
 }
 
 void HistoryDatabase::BeginTransaction() {
@@ -283,21 +275,24 @@ sql::InitStatus HistoryDatabase::EnsureCurrentVersion(
     meta_table_.SetVersionNumber(cur_version);
   }
 
-  if (cur_version == 17)
-    needs_version_18_migration_ = true;
+  if (cur_version == 17) {
+    // Version 17 was for thumbnails to top sites migration. We ended up
+    // disabling it though, so 17->18 does nothing.
+    ++cur_version;
+    meta_table_.SetVersionNumber(cur_version);
+  }
 
-  if (!CommandLine::ForCurrentProcess()->HasSwitch(switches::kTopSites) &&
-      cur_version == 18) {
-    // Set DB version back to pre-top sites.
-    cur_version = 17;
+  if (cur_version == 18) {
+    // This is the version prior to adding url_source column. We need to
+    // migrate the database.
+    cur_version = 19;
     meta_table_.SetVersionNumber(cur_version);
   }
 
   // When the version is too old, we just try to continue anyway, there should
   // not be a released product that makes a database too old for us to handle.
-  LOG_IF(WARNING, (cur_version < GetCurrentVersion() &&
-                   !needs_version_18_migration_)) <<
-      "History database version " << cur_version << " is too old to handle.";
+  LOG_IF(WARNING, cur_version < GetCurrentVersion()) <<
+         "History database version " << cur_version << " is too old to handle.";
 
   return sql::INIT_OK;
 }
@@ -328,10 +323,7 @@ void HistoryDatabase::MigrateTimeEpoch() {
 #endif
 
 void HistoryDatabase::MigrationToTopSitesDone() {
-  // We should be migrating from 17 to 18.
-  DCHECK_EQ(17, meta_table_.GetVersionNumber());
-  meta_table_.SetVersionNumber(18);
-  needs_version_18_migration_ = false;
+  // TODO(sky): implement me.
 }
 
 }  // namespace history
diff --git a/chrome/browser/history/history_database.h b/chrome/browser/history/history_database.h
index 3b3414a..fe74e89 100644
--- a/chrome/browser/history/history_database.h
+++ b/chrome/browser/history/history_database.h
@@ -4,6 +4,7 @@
 
 #ifndef CHROME_BROWSER_HISTORY_HISTORY_DATABASE_H_
 #define CHROME_BROWSER_HISTORY_HISTORY_DATABASE_H_
+#pragma once
 
 #include "app/sql/connection.h"
 #include "app/sql/init_status.h"
@@ -122,14 +123,6 @@ class HistoryDatabase : public DownloadDatabase,
     return needs_version_17_migration_;
   }
 
-  // Returns true if the Thumbnails database should be renamed to
-  // Favicons database. 17 -> 18 is migration to TopSites. ThumbnailsDatabase
-  // doesn't store the thumbnails any more, only the favicons. Hence, its file
-  // is renamed from Thumbnails to Favicons.
-  bool needs_version_18_migration() const {
-    return needs_version_18_migration_;
-  }
-
   // Update the database version after the TopSites migration.
   void MigrationToTopSitesDone();
 
@@ -178,7 +171,6 @@ class HistoryDatabase : public DownloadDatabase,
 
   // See the getters above.
   bool needs_version_17_migration_;
-  bool needs_version_18_migration_;
 
   DISALLOW_COPY_AND_ASSIGN(HistoryDatabase);
 };
diff --git a/chrome/browser/history/history_marshaling.h b/chrome/browser/history/history_marshaling.h
index 39b8983..1efd670 100644
--- a/chrome/browser/history/history_marshaling.h
+++ b/chrome/browser/history/history_marshaling.h
@@ -7,6 +7,7 @@
 
 #ifndef CHROME_BROWSER_HISTORY_HISTORY_MARSHALING_H__
 #define CHROME_BROWSER_HISTORY_HISTORY_MARSHALING_H__
+#pragma once
 
 #include "base/scoped_vector.h"
 #include "chrome/browser/cancelable_request.h"
@@ -16,49 +17,6 @@
 
 namespace history {
 
-// Navigation -----------------------------------------------------------------
-
-// Marshalling structure for AddPage.
-class HistoryAddPageArgs
-    : public base::RefCountedThreadSafe<HistoryAddPageArgs> {
- public:
-  HistoryAddPageArgs(const GURL& arg_url,
-                     base::Time arg_time,
-                     const void* arg_id_scope,
-                     int32 arg_page_id,
-                     const GURL& arg_referrer,
-                     const history::RedirectList& arg_redirects,
-                     PageTransition::Type arg_transition,
-                     bool arg_did_replace_entry)
-      : url(arg_url),
-        time(arg_time),
-        id_scope(arg_id_scope),
-        page_id(arg_page_id),
-        referrer(arg_referrer),
-        redirects(arg_redirects),
-        transition(arg_transition),
-        did_replace_entry(arg_did_replace_entry) {
-  }
-
-  GURL url;
-  base::Time time;
-
-  const void* id_scope;
-  int32 page_id;
-
-  GURL referrer;
-  history::RedirectList redirects;
-  PageTransition::Type transition;
-  bool did_replace_entry;
-
- private:
-  friend class base::RefCountedThreadSafe<HistoryAddPageArgs>;
-
-  ~HistoryAddPageArgs() {}
-
-  DISALLOW_COPY_AND_ASSIGN(HistoryAddPageArgs);
-};
-
 // Querying -------------------------------------------------------------------
 
 typedef CancelableRequest1<HistoryService::QueryURLCallback,
@@ -104,10 +62,6 @@ typedef CancelableRequest1<HistoryService::DownloadQueryCallback,
 typedef CancelableRequest<HistoryService::DownloadCreateCallback>
     DownloadCreateRequest;
 
-typedef CancelableRequest1<HistoryService::DownloadSearchCallback,
-                          std::vector<int64> >
-    DownloadSearchRequest;
-
 // Deletion --------------------------------------------------------------------
 
 typedef CancelableRequest<HistoryService::ExpireHistoryCallback>
diff --git a/chrome/browser/history/history_notifications.h b/chrome/browser/history/history_notifications.h
index 80fc9d5..3957041 100644
--- a/chrome/browser/history/history_notifications.h
+++ b/chrome/browser/history/history_notifications.h
@@ -6,6 +6,7 @@
 
 #ifndef CHROME_BROWSER_HISTORY_HISTORY_NOTIFICATIONS_H__
 #define CHROME_BROWSER_HISTORY_HISTORY_NOTIFICATIONS_H__
+#pragma once
 
 #include <set>
 #include <vector>
diff --git a/chrome/browser/history/history_publisher.h b/chrome/browser/history/history_publisher.h
index 5fafc3e..fdf94b7 100644
--- a/chrome/browser/history/history_publisher.h
+++ b/chrome/browser/history/history_publisher.h
@@ -4,9 +4,9 @@
 
 #ifndef CHROME_BROWSER_HISTORY_HISTORY_PUBLISHER_H_
 #define CHROME_BROWSER_HISTORY_HISTORY_PUBLISHER_H_
+#pragma once
 
 #include <vector>
-#include <string>
 
 #include "base/basictypes.h"
 #include "base/string16.h"
diff --git a/chrome/browser/history/history_publisher_win.cc b/chrome/browser/history/history_publisher_win.cc
index cbde619..3a7a548 100644
--- a/chrome/browser/history/history_publisher_win.cc
+++ b/chrome/browser/history/history_publisher_win.cc
@@ -15,6 +15,7 @@
 #include "base/scoped_variant_win.h"
 #include "base/string_util.h"
 #include "base/time.h"
+#include "base/utf_string_conversions.h"
 #include "googleurl/src/gurl.h"
 
 namespace {
@@ -119,7 +120,10 @@ void HistoryPublisher::PublishDataToIndexers(const PageData& page_data)
   ScopedBstr url(ASCIIToWide(page_data.url.spec()).c_str());
   ScopedBstr html(page_data.html);
   ScopedBstr title(page_data.title);
-  ScopedBstr format(ASCIIToWide(page_data.thumbnail_format).c_str());
+  // Don't send a NULL string through ASCIIToWide.
+  ScopedBstr format(page_data.thumbnail_format ?
+      ASCIIToWide(page_data.thumbnail_format).c_str() :
+      NULL);
   ScopedVariant psa(thumbnail_arr.m_psa);
   for (size_t i = 0; i < indexers_.size(); ++i) {
     indexers_[i]->SendPageData(time, url, html, title, format, psa);
diff --git a/chrome/browser/history/history_querying_unittest.cc b/chrome/browser/history/history_querying_unittest.cc
index 7512786..c752d3f 100644
--- a/chrome/browser/history/history_querying_unittest.cc
+++ b/chrome/browser/history/history_querying_unittest.cc
@@ -7,6 +7,7 @@
 #include "base/file_path.h"
 #include "base/file_util.h"
 #include "base/path_service.h"
+#include "base/scoped_temp_dir.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/history/history.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -86,11 +87,9 @@ class HistoryQueryTest : public testing::Test {
 
  private:
   virtual void SetUp() {
-    FilePath temp_dir;
-    PathService::Get(base::DIR_TEMP, &temp_dir);
-    history_dir_ = temp_dir.AppendASCII("HistoryTest");
-    file_util::Delete(history_dir_, true);
-    file_util::CreateDirectory(history_dir_);
+    ASSERT_TRUE(temp_dir_.CreateUniqueTempDir());
+    history_dir_ = temp_dir_.path().AppendASCII("HistoryTest");
+    ASSERT_TRUE(file_util::CreateDirectory(history_dir_));
 
     history_ = new HistoryService;
     if (!history_->Init(history_dir_, NULL)) {
@@ -111,7 +110,7 @@ class HistoryQueryTest : public testing::Test {
 
       history_->AddPage(url, test_entries[i].time, id_scope, page_id, GURL(),
                         PageTransition::LINK, history::RedirectList(),
-                        false);
+                        history::SOURCE_BROWSED, false);
       history_->SetPageTitle(url, UTF8ToUTF16(test_entries[i].title));
       history_->SetPageContents(url, UTF8ToUTF16(test_entries[i].body));
     }
@@ -124,7 +123,6 @@ class HistoryQueryTest : public testing::Test {
       history_ = NULL;
       MessageLoop::current()->Run();  // Wait for the other thread.
     }
-    file_util::Delete(history_dir_, true);
   }
 
   void QueryHistoryComplete(HistoryService::Handle, QueryResults* results) {
@@ -132,6 +130,8 @@ class HistoryQueryTest : public testing::Test {
     MessageLoop::current()->Quit();  // Will return out to QueryHistory.
   }
 
+  ScopedTempDir temp_dir_;
+
   MessageLoop message_loop_;
 
   FilePath history_dir_;
@@ -314,7 +314,7 @@ TEST_F(HistoryQueryTest, FTSArchived) {
   row2.set_last_visit(Time::Now());
   urls_to_add.push_back(row2);
 
-  history_->AddPagesWithDetails(urls_to_add);
+  history_->AddPagesWithDetails(urls_to_add, history::SOURCE_BROWSED);
 
   QueryOptions options;
   QueryResults results;
diff --git a/chrome/browser/history/history_types.cc b/chrome/browser/history/history_types.cc
index 50395aa..8a8ce6d 100644
--- a/chrome/browser/history/history_types.cc
+++ b/chrome/browser/history/history_types.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -10,11 +10,43 @@
 #include "base/stl_util-inl.h"
 
 using base::Time;
+using base::TimeDelta;
 
 namespace history {
 
 // URLRow ----------------------------------------------------------------------
 
+URLRow::URLRow() {
+  Initialize();
+}
+
+URLRow::URLRow(const GURL& url) : url_(url) {
+  // Initialize will not set the URL, so our initialization above will stay.
+  Initialize();
+}
+
+URLRow::URLRow(const GURL& url, URLID id) : url_(url) {
+  // Initialize will not set the URL, so our initialization above will stay.
+  Initialize();
+  // Initialize will zero the id_, so set it here.
+  id_ = id;
+}
+
+URLRow::~URLRow() {
+}
+
+URLRow& URLRow::operator=(const URLRow& other) {
+  id_ = other.id_;
+  url_ = other.url_;
+  title_ = other.title_;
+  visit_count_ = other.visit_count_;
+  typed_count_ = other.typed_count_;
+  last_visit_ = other.last_visit_;
+  hidden_ = other.hidden_;
+  favicon_id_ = other.favicon_id_;
+  return *this;
+}
+
 void URLRow::Swap(URLRow* other) {
   std::swap(id_, other->id_);
   url_.Swap(&other->url_);
@@ -60,6 +92,9 @@ VisitRow::VisitRow(URLID arg_url_id,
       is_indexed(false) {
 }
 
+VisitRow::~VisitRow() {
+}
+
 // StarredEntry ----------------------------------------------------------------
 
 StarredEntry::StarredEntry()
@@ -71,6 +106,9 @@ StarredEntry::StarredEntry()
       url_id(0) {
 }
 
+StarredEntry::~StarredEntry() {
+}
+
 void StarredEntry::Swap(StarredEntry* other) {
   std::swap(id, other->id);
   title.swap(other->title);
@@ -86,6 +124,23 @@ void StarredEntry::Swap(StarredEntry* other) {
 
 // URLResult -------------------------------------------------------------------
 
+URLResult::URLResult() {
+}
+
+URLResult::URLResult(const GURL& url, base::Time visit_time)
+    : URLRow(url),
+      visit_time_(visit_time) {
+}
+
+URLResult::URLResult(const GURL& url,
+                     const Snippet::MatchPositions& title_matches)
+    : URLRow(url) {
+  title_match_positions_ = title_matches;
+}
+
+URLResult::~URLResult() {
+}
+
 void URLResult::Swap(URLResult* other) {
   URLRow::Swap(other);
   std::swap(visit_time_, other->visit_time_);
@@ -237,4 +292,34 @@ void QueryResults::AdjustResultMap(size_t begin, size_t end, ptrdiff_t delta) {
   }
 }
 
+HistoryAddPageArgs::HistoryAddPageArgs(
+    const GURL& arg_url,
+    base::Time arg_time,
+    const void* arg_id_scope,
+    int32 arg_page_id,
+    const GURL& arg_referrer,
+    const history::RedirectList& arg_redirects,
+    PageTransition::Type arg_transition,
+    VisitSource arg_source,
+    bool arg_did_replace_entry)
+      : url(arg_url),
+        time(arg_time),
+        id_scope(arg_id_scope),
+        page_id(arg_page_id),
+        referrer(arg_referrer),
+        redirects(arg_redirects),
+        transition(arg_transition),
+        visit_source(arg_source),
+        did_replace_entry(arg_did_replace_entry) {
+}
+
+HistoryAddPageArgs::~HistoryAddPageArgs() {
+}
+
+HistoryAddPageArgs* HistoryAddPageArgs::Clone() const {
+  return new HistoryAddPageArgs(
+      url, time, id_scope, page_id, referrer, redirects, transition,
+      visit_source, did_replace_entry);
+}
+
 }  // namespace history
diff --git a/chrome/browser/history/history_types.h b/chrome/browser/history/history_types.h
index f7bc7fb..8fab602 100644
--- a/chrome/browser/history/history_types.h
+++ b/chrome/browser/history/history_types.h
@@ -4,19 +4,23 @@
 
 #ifndef CHROME_BROWSER_HISTORY_HISTORY_TYPES_H_
 #define CHROME_BROWSER_HISTORY_HISTORY_TYPES_H_
+#pragma once
 
+#include <deque>
 #include <map>
 #include <set>
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
+#include "base/ref_counted_memory.h"
 #include "base/stack_container.h"
 #include "base/string16.h"
 #include "base/time.h"
 #include "chrome/browser/history/snippet.h"
 #include "chrome/common/page_transition_types.h"
 #include "chrome/common/ref_counted_util.h"
+#include "chrome/common/thumbnail_score.h"
 #include "googleurl/src/gurl.h"
 
 namespace history {
@@ -56,25 +60,16 @@ typedef int64 URLID;
 // dirty bits will not be in sync for these copies.
 class URLRow {
  public:
-  URLRow() {
-    Initialize();
-  }
+  URLRow();
 
-  explicit URLRow(const GURL& url) : url_(url) {
-    // Initialize will not set the URL, so our initialization above will stay.
-    Initialize();
-  }
+  explicit URLRow(const GURL& url);
 
   // We need to be able to set the id of a URLRow that's being passed through
   // an IPC message.  This constructor should probably not be used otherwise.
-  URLRow(const GURL& url, URLID id) : url_(url) {
-    // Initialize will not set the URL, so our initialization above will stay.
-    Initialize();
-    // Initialize will zero the id_, so set it here.
-    id_ = id;
-  }
+  URLRow(const GURL& url, URLID id);
 
-  virtual ~URLRow() {}
+  virtual ~URLRow();
+  URLRow& operator=(const URLRow& other);
 
   URLID id() const { return id_; }
   const GURL& url() const { return url_; }
@@ -172,9 +167,27 @@ class URLRow {
   // We support the implicit copy constuctor and operator=.
 };
 
-// VisitRow -------------------------------------------------------------------
+// The enumeration of all possible sources of visits is listed below.
+// The source will be propogated along with a URL or a visit item
+// and eventually be stored in the history database,
+// visit_source table specifically.
+// Different from page transition types, they describe the origins of visits.
+// (Warning): Please don't change any existing values while it is ok to add
+// new values when needed.
+typedef enum {
+  SOURCE_SYNCED = 0,         // Synchronized from somewhere else.
+  SOURCE_BROWSED = 1,        // User browsed.
+  SOURCE_EXTENSION = 2,      // Added by an externsion.
+  SOURCE_FIREFOX_IMPORTED = 3,
+  SOURCE_IE_IMPORTED = 4,
+  SOURCE_SAFARI_IMPORTED = 5,
+} VisitSource;
 
 typedef int64 VisitID;
+// Structure to hold the mapping between each visit's id and its source.
+typedef std::map<VisitID, VisitSource> VisitSourceMap;
+
+// VisitRow -------------------------------------------------------------------
 
 // Holds all information associated with a specific visit. A visit holds time
 // and referrer information for one time a URL is visited.
@@ -186,6 +199,7 @@ class VisitRow {
            VisitID arg_referring_visit,
            PageTransition::Type arg_transition,
            SegmentID arg_segment_id);
+  ~VisitRow();
 
   // ID of this row (visit ID, used a a referrer for other visits).
   VisitID visit_id;
@@ -277,6 +291,7 @@ struct StarredEntry {
   };
 
   StarredEntry();
+  ~StarredEntry();
 
   void Swap(StarredEntry* other);
 
@@ -310,7 +325,7 @@ struct StarredEntry {
 
   // If type == URL, this is the ID of the URL of the primary page that was
   // starred.
-  history::URLID url_id;
+  URLID url_id;
 
   // Time the entry was last modified. This is only used for groups and
   // indicates the last time a URL was added as a child to the group.
@@ -321,17 +336,12 @@ struct StarredEntry {
 
 class URLResult : public URLRow {
  public:
-  URLResult() {}
-  URLResult(const GURL& url, base::Time visit_time)
-      : URLRow(url),
-        visit_time_(visit_time) {
-  }
+  URLResult();
+  URLResult(const GURL& url, base::Time visit_time);
   // Constructor that create a URLResult from the specified URL and title match
   // positions from title_matches.
-  URLResult(const GURL& url, const Snippet::MatchPositions& title_matches)
-      : URLRow(url) {
-    title_match_positions_ = title_matches;
-  }
+  URLResult(const GURL& url, const Snippet::MatchPositions& title_matches);
+  ~URLResult();
 
   base::Time visit_time() const { return visit_time_; }
   void set_visit_time(base::Time visit_time) { visit_time_ = visit_time; }
@@ -525,8 +535,57 @@ struct MostVisitedURL {
   }
 };
 
+// Used by TopSites to store the thumbnails.
+struct Images {
+  scoped_refptr<RefCountedBytes> thumbnail;
+  ThumbnailScore thumbnail_score;
+
+  // TODO(brettw): this will eventually store the favicon.
+  // scoped_refptr<RefCountedBytes> favicon;
+};
+
 typedef std::vector<MostVisitedURL> MostVisitedURLList;
 
-}  // history
+// Navigation -----------------------------------------------------------------
+
+// Marshalling structure for AddPage.
+class HistoryAddPageArgs
+    : public base::RefCountedThreadSafe<HistoryAddPageArgs> {
+ public:
+  HistoryAddPageArgs(const GURL& arg_url,
+                     base::Time arg_time,
+                     const void* arg_id_scope,
+                     int32 arg_page_id,
+                     const GURL& arg_referrer,
+                     const history::RedirectList& arg_redirects,
+                     PageTransition::Type arg_transition,
+                     VisitSource arg_source,
+                     bool arg_did_replace_entry);
+
+  // Returns a new HistoryAddPageArgs that is a copy of this (ref count is
+  // of course reset). Ownership of returned object passes to caller.
+  HistoryAddPageArgs* Clone() const;
+
+  GURL url;
+  base::Time time;
+
+  const void* id_scope;
+  int32 page_id;
+
+  GURL referrer;
+  history::RedirectList redirects;
+  PageTransition::Type transition;
+  VisitSource visit_source;
+  bool did_replace_entry;
+
+ private:
+  friend class base::RefCountedThreadSafe<HistoryAddPageArgs>;
+
+  ~HistoryAddPageArgs();
+
+  DISALLOW_COPY_AND_ASSIGN(HistoryAddPageArgs);
+};
+
+}  // namespace history
 
 #endif  // CHROME_BROWSER_HISTORY_HISTORY_TYPES_H_
diff --git a/chrome/browser/history/history_unittest.cc b/chrome/browser/history/history_unittest.cc
index c8db05a..53d91c6 100644
--- a/chrome/browser/history/history_unittest.cc
+++ b/chrome/browser/history/history_unittest.cc
@@ -24,15 +24,19 @@
 #include "app/sql/statement.h"
 #include "base/basictypes.h"
 #include "base/callback.h"
+#include "base/command_line.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
 #include "base/message_loop.h"
 #include "base/path_service.h"
+#include "base/scoped_temp_dir.h"
 #include "base/scoped_vector.h"
 #include "base/string_util.h"
 #include "base/task.h"
+#include "base/utf_string_conversions.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/download/download_item.h"
+#include "chrome/browser/history/download_create_info.h"
 #include "chrome/browser/history/history.h"
 #include "chrome/browser/history/history_backend.h"
 #include "chrome/browser/history/history_database.h"
@@ -40,7 +44,9 @@
 #include "chrome/browser/history/in_memory_database.h"
 #include "chrome/browser/history/in_memory_history_backend.h"
 #include "chrome/browser/history/page_usage_data.h"
+#include "chrome/browser/history/top_sites.h"
 #include "chrome/common/chrome_paths.h"
+#include "chrome/common/chrome_switches.h"
 #include "chrome/common/notification_service.h"
 #include "chrome/common/thumbnail_score.h"
 #include "chrome/tools/profiles/thumbnail-inl.h"
@@ -163,11 +169,9 @@ class HistoryTest : public testing::Test {
 
   // testing::Test
   virtual void SetUp() {
-    FilePath temp_dir;
-    PathService::Get(base::DIR_TEMP, &temp_dir);
-    history_dir_ = temp_dir.AppendASCII("HistoryTest");
-    file_util::Delete(history_dir_, true);
-    file_util::CreateDirectory(history_dir_);
+    ASSERT_TRUE(temp_dir_.CreateUniqueTempDir());
+    history_dir_ = temp_dir_.path().AppendASCII("HistoryTest");
+    ASSERT_TRUE(file_util::CreateDirectory(history_dir_));
   }
 
   void DeleteBackend() {
@@ -183,9 +187,6 @@ class HistoryTest : public testing::Test {
     if (history_service_)
       CleanupHistoryService();
 
-    // Try to clean up the database file.
-    file_util::Delete(history_dir_, true);
-
     // Make sure we don't have any event pending that could disrupt the next
     // test.
     MessageLoop::current()->PostTask(FROM_HERE, new MessageLoop::QuitTask);
@@ -261,6 +262,8 @@ class HistoryTest : public testing::Test {
     MessageLoop::current()->Quit();
   }
 
+  ScopedTempDir temp_dir_;
+
   MessageLoopForUI message_loop_;
 
   // PageUsageData vector to test segments.
@@ -413,7 +416,8 @@ TEST_F(HistoryTest, AddPage) {
   const GURL test_url("http://www.google.com/");
   history->AddPage(test_url, NULL, 0, GURL(),
                    PageTransition::MANUAL_SUBFRAME,
-                   history::RedirectList(), false);
+                   history::RedirectList(),
+                   history::SOURCE_BROWSED, false);
   EXPECT_TRUE(QueryURL(history, test_url));
   EXPECT_EQ(1, query_url_row_.visit_count());
   EXPECT_EQ(0, query_url_row_.typed_count());
@@ -421,7 +425,8 @@ TEST_F(HistoryTest, AddPage) {
 
   // Add the page once from the main frame (should unhide it).
   history->AddPage(test_url, NULL, 0, GURL(), PageTransition::LINK,
-                   history::RedirectList(), false);
+                   history::RedirectList(),
+                   history::SOURCE_BROWSED, false);
   EXPECT_TRUE(QueryURL(history, test_url));
   EXPECT_EQ(2, query_url_row_.visit_count());  // Added twice.
   EXPECT_EQ(0, query_url_row_.typed_count());  // Never typed.
@@ -444,14 +449,16 @@ TEST_F(HistoryTest, AddPageSameTimes) {
   // additions have different timestamps.
   history->AddPage(test_urls[0], now, NULL, 0, GURL(),
                    PageTransition::LINK,
-                   history::RedirectList(), false);
+                   history::RedirectList(),
+                   history::SOURCE_BROWSED, false);
   EXPECT_TRUE(QueryURL(history, test_urls[0]));
   EXPECT_EQ(1, query_url_row_.visit_count());
   EXPECT_TRUE(now == query_url_row_.last_visit());  // gtest doesn't like Time
 
   history->AddPage(test_urls[1], now, NULL, 0, GURL(),
                    PageTransition::LINK,
-                   history::RedirectList(), false);
+                   history::RedirectList(),
+                   history::SOURCE_BROWSED, false);
   EXPECT_TRUE(QueryURL(history, test_urls[1]));
   EXPECT_EQ(1, query_url_row_.visit_count());
   EXPECT_TRUE(now + TimeDelta::FromMicroseconds(1) ==
@@ -461,7 +468,8 @@ TEST_F(HistoryTest, AddPageSameTimes) {
   history->AddPage(test_urls[2], now + TimeDelta::FromMinutes(1),
                    NULL, 0, GURL(),
                    PageTransition::LINK,
-                   history::RedirectList(), false);
+                   history::RedirectList(),
+                   history::SOURCE_BROWSED, false);
   EXPECT_TRUE(QueryURL(history, test_urls[2]));
   EXPECT_EQ(1, query_url_row_.visit_count());
   EXPECT_TRUE(now + TimeDelta::FromMinutes(1) ==
@@ -484,7 +492,8 @@ TEST_F(HistoryTest, AddRedirect) {
   // Add the sequence of pages as a server with no referrer. Note that we need
   // to have a non-NULL page ID scope.
   history->AddPage(first_redirects.back(), MakeFakeHost(1), 0, GURL(),
-                   PageTransition::LINK, first_redirects, true);
+                   PageTransition::LINK, first_redirects,
+                   history::SOURCE_BROWSED,  true);
 
   // The first page should be added once with a link visit type (because we set
   // LINK when we added the original URL, and a referrer of nowhere (0).
@@ -522,7 +531,7 @@ TEST_F(HistoryTest, AddRedirect) {
                    second_redirects[0],
                    static_cast<PageTransition::Type>(PageTransition::LINK |
                        PageTransition::CLIENT_REDIRECT),
-                   second_redirects, true);
+                   second_redirects, history::SOURCE_BROWSED, true);
 
   // The last page (source of the client redirect) should NOT have an
   // additional visit added, because it was a client redirect (normally it
@@ -547,7 +556,8 @@ TEST_F(HistoryTest, Typed) {
   // Add the page once as typed.
   const GURL test_url("http://www.google.com/");
   history->AddPage(test_url, NULL, 0, GURL(), PageTransition::TYPED,
-                   history::RedirectList(), false);
+                   history::RedirectList(),
+                   history::SOURCE_BROWSED, false);
   EXPECT_TRUE(QueryURL(history, test_url));
 
   // We should have the same typed & visit count.
@@ -556,7 +566,8 @@ TEST_F(HistoryTest, Typed) {
 
   // Add the page again not typed.
   history->AddPage(test_url, NULL, 0, GURL(), PageTransition::LINK,
-                   history::RedirectList(), false);
+                   history::RedirectList(),
+                   history::SOURCE_BROWSED, false);
   EXPECT_TRUE(QueryURL(history, test_url));
 
   // The second time should not have updated the typed count.
@@ -566,7 +577,7 @@ TEST_F(HistoryTest, Typed) {
   // Add the page again as a generated URL.
   history->AddPage(test_url, NULL, 0, GURL(),
                    PageTransition::GENERATED, history::RedirectList(),
-                   false);
+                   history::SOURCE_BROWSED, false);
   EXPECT_TRUE(QueryURL(history, test_url));
 
   // This should have worked like a link click.
@@ -576,7 +587,7 @@ TEST_F(HistoryTest, Typed) {
   // Add the page again as a reload.
   history->AddPage(test_url, NULL, 0, GURL(),
                    PageTransition::RELOAD, history::RedirectList(),
-                   false);
+                   history::SOURCE_BROWSED, false);
   EXPECT_TRUE(QueryURL(history, test_url));
 
   // This should not have incremented any visit counts.
@@ -591,7 +602,7 @@ TEST_F(HistoryTest, SetTitle) {
 
   // Add a URL.
   const GURL existing_url("http://www.google.com/");
-  history->AddPage(existing_url);
+  history->AddPage(existing_url, history::SOURCE_BROWSED);
 
   // Set some title.
   const string16 existing_title = UTF8ToUTF16("Google");
@@ -626,7 +637,7 @@ TEST_F(HistoryTest, Segments) {
   const GURL existing_url("http://www.google.com/");
   history->AddPage(existing_url, scope, 0, GURL(),
                    PageTransition::TYPED, history::RedirectList(),
-                   false);
+                   history::SOURCE_BROWSED, false);
 
   // Make sure a segment was created.
   history->QuerySegmentUsageSince(
@@ -645,7 +656,7 @@ TEST_F(HistoryTest, Segments) {
   const GURL link_url("http://yahoo.com/");
   history->AddPage(link_url, scope, 0, GURL(),
                    PageTransition::LINK, history::RedirectList(),
-                   false);
+                   history::SOURCE_BROWSED, false);
 
   // Query again
   history->QuerySegmentUsageSince(
@@ -663,7 +674,7 @@ TEST_F(HistoryTest, Segments) {
   // Add a page linked from existing_url.
   history->AddPage(GURL("http://www.google.com/foo"), scope, 3, existing_url,
                    PageTransition::LINK, history::RedirectList(),
-                   false);
+                   history::SOURCE_BROWSED, false);
 
   // Query again
   history->QuerySegmentUsageSince(
@@ -685,6 +696,9 @@ TEST_F(HistoryTest, Segments) {
 // This just tests history system -> thumbnail database integration, the actual
 // thumbnail tests are in its own file.
 TEST_F(HistoryTest, Thumbnails) {
+  if (history::TopSites::IsEnabled())
+    return;  // TopSitesTest replaces this.
+
   scoped_refptr<HistoryService> history(new HistoryService);
   history_service_ = history;
   ASSERT_TRUE(history->Init(history_dir_, NULL));
@@ -694,7 +708,8 @@ TEST_F(HistoryTest, Thumbnails) {
   static const double boringness = 0.25;
 
   const GURL url("http://www.google.com/thumbnail_test/");
-  history->AddPage(url);  // Must be visited before adding a thumbnail.
+  // Must be visited before adding a thumbnail.
+  history->AddPage(url, history::SOURCE_BROWSED);
   history->SetPageThumbnail(url, *thumbnail,
                             ThumbnailScore(boringness, true, true));
 
@@ -761,10 +776,10 @@ TEST_F(HistoryTest, MostVisitedURLs) {
   // Add two pages.
   history->AddPage(url0, scope, 0, GURL(),
                    PageTransition::TYPED, history::RedirectList(),
-                   false);
+                   history::SOURCE_BROWSED, false);
   history->AddPage(url1, scope, 0, GURL(),
                    PageTransition::TYPED, history::RedirectList(),
-                   false);
+                   history::SOURCE_BROWSED, false);
   history->QueryMostVisitedURLs(20, 90, &consumer_,
                                 NewCallback(static_cast<HistoryTest*>(this),
                                     &HistoryTest::OnMostVisitedURLsAvailable));
@@ -777,7 +792,7 @@ TEST_F(HistoryTest, MostVisitedURLs) {
   // Add another page.
   history->AddPage(url2, scope, 0, GURL(),
                    PageTransition::TYPED, history::RedirectList(),
-                   false);
+                   history::SOURCE_BROWSED, false);
   history->QueryMostVisitedURLs(20, 90, &consumer_,
                                 NewCallback(static_cast<HistoryTest*>(this),
                                     &HistoryTest::OnMostVisitedURLsAvailable));
@@ -791,7 +806,7 @@ TEST_F(HistoryTest, MostVisitedURLs) {
   // Revisit url2, making it the top URL.
   history->AddPage(url2, scope, 0, GURL(),
                    PageTransition::TYPED, history::RedirectList(),
-                   false);
+                   history::SOURCE_BROWSED, false);
   history->QueryMostVisitedURLs(20, 90, &consumer_,
                                 NewCallback(static_cast<HistoryTest*>(this),
                                     &HistoryTest::OnMostVisitedURLsAvailable));
@@ -805,7 +820,7 @@ TEST_F(HistoryTest, MostVisitedURLs) {
   // Revisit url1, making it the top URL.
   history->AddPage(url1, scope, 0, GURL(),
                    PageTransition::TYPED, history::RedirectList(),
-                   false);
+                   history::SOURCE_BROWSED, false);
   history->QueryMostVisitedURLs(20, 90, &consumer_,
                                 NewCallback(static_cast<HistoryTest*>(this),
                                     &HistoryTest::OnMostVisitedURLsAvailable));
@@ -824,7 +839,7 @@ TEST_F(HistoryTest, MostVisitedURLs) {
   // Visit url4 using redirects.
   history->AddPage(url4, scope, 0, GURL(),
                    PageTransition::TYPED, redirects,
-                   false);
+                   history::SOURCE_BROWSED, false);
   history->QueryMostVisitedURLs(20, 90, &consumer_,
                                 NewCallback(static_cast<HistoryTest*>(this),
                                     &HistoryTest::OnMostVisitedURLsAvailable));
@@ -882,7 +897,8 @@ HistoryAddPageArgs* MakeAddArgs(const GURL& url) {
                                 0,
                                 GURL(),
                                 history::RedirectList(),
-                                PageTransition::TYPED, false);
+                                PageTransition::TYPED,
+                                history::SOURCE_BROWSED, false);
 }
 
 // Convenience version of the above to convert a char string.
diff --git a/chrome/browser/history/in_memory_database.h b/chrome/browser/history/in_memory_database.h
index 62460dd..27e1091 100644
--- a/chrome/browser/history/in_memory_database.h
+++ b/chrome/browser/history/in_memory_database.h
@@ -1,11 +1,10 @@
-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_HISTORY_IN_MEMORY_DATABASE_H_
 #define CHROME_BROWSER_HISTORY_IN_MEMORY_DATABASE_H_
-
-#include <string>
+#pragma once
 
 #include "app/sql/connection.h"
 #include "base/basictypes.h"
diff --git a/chrome/browser/history/in_memory_history_backend.cc b/chrome/browser/history/in_memory_history_backend.cc
index 9f3e7be..b3d5da9 100644
--- a/chrome/browser/history/in_memory_history_backend.cc
+++ b/chrome/browser/history/in_memory_history_backend.cc
@@ -5,13 +5,19 @@
 #include "chrome/browser/history/in_memory_history_backend.h"
 
 #include "base/command_line.h"
+#include "base/histogram.h"
+#include "base/time.h"
+#include "base/utf_string_conversions.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/history/history_notifications.h"
 #include "chrome/browser/history/in_memory_database.h"
 #include "chrome/browser/history/in_memory_url_index.h"
+#include "chrome/browser/history/url_database.h"
+#include "chrome/browser/prefs/pref_service.h"
 #include "chrome/browser/profile.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/notification_service.h"
+#include "chrome/common/pref_names.h"
 
 namespace history {
 
@@ -26,14 +32,19 @@ InMemoryHistoryBackend::InMemoryHistoryBackend()
 InMemoryHistoryBackend::~InMemoryHistoryBackend() {
 }
 
-bool InMemoryHistoryBackend::Init(const FilePath& history_filename) {
+bool InMemoryHistoryBackend::Init(const FilePath& history_filename,
+                                  URLDatabase* db) {
   db_.reset(new InMemoryDatabase);
   bool success = db_->InitFromDisk(history_filename);
 
   if (CommandLine::ForCurrentProcess()->HasSwitch(
       switches::kEnableInMemoryURLIndex)) {
-    index_.reset(new InMemoryURLIndex);
-    // TODO(rohitrao): Load index.
+    index_.reset(new InMemoryURLIndex());
+    base::TimeTicks beginning_time = base::TimeTicks::Now();
+    // TODO(mrossetti): Provide languages when profile is available.
+    index_->Init(db, std::string());
+    UMA_HISTOGRAM_TIMES("Autocomplete.HistoryDatabaseIndexingTime",
+                        base::TimeTicks::Now() - beginning_time);
   }
 
   return success;
diff --git a/chrome/browser/history/in_memory_history_backend.h b/chrome/browser/history/in_memory_history_backend.h
index 30026b5..bfa51d8 100644
--- a/chrome/browser/history/in_memory_history_backend.h
+++ b/chrome/browser/history/in_memory_history_backend.h
@@ -12,12 +12,12 @@
 
 #ifndef CHROME_BROWSER_HISTORY_IN_MEMORY_HISTORY_BACKEND_H_
 #define CHROME_BROWSER_HISTORY_IN_MEMORY_HISTORY_BACKEND_H_
-
-#include <string>
+#pragma once
 
 #include "base/basictypes.h"
 #include "base/gtest_prod_util.h"
 #include "base/scoped_ptr.h"
+#include "chrome/common/notification_observer.h"
 #include "chrome/common/notification_registrar.h"
 
 class FilePath;
@@ -28,6 +28,7 @@ namespace history {
 
 class InMemoryDatabase;
 class InMemoryURLIndex;
+class URLDatabase;
 struct URLsDeletedDetails;
 struct URLsModifiedDetails;
 
@@ -37,7 +38,7 @@ class InMemoryHistoryBackend : public NotificationObserver {
   ~InMemoryHistoryBackend();
 
   // Initializes with data from the given history database.
-  bool Init(const FilePath& history_filename);
+  bool Init(const FilePath& history_filename, URLDatabase* db);
 
   // Does initialization work when this object is attached to the history
   // system on the main thread. The argument is the profile with which the
diff --git a/chrome/browser/history/in_memory_url_index.cc b/chrome/browser/history/in_memory_url_index.cc
index 83c401f..95afa57 100644
--- a/chrome/browser/history/in_memory_url_index.cc
+++ b/chrome/browser/history/in_memory_url_index.cc
@@ -4,10 +4,495 @@
 
 #include "chrome/browser/history/in_memory_url_index.h"
 
+#include <algorithm>
+#include <limits>
+
+#include "app/l10n_util.h"
+#include "base/i18n/word_iterator.h"
+#include "base/string_util.h"
+#include "base/time.h"
+#include "base/utf_string_conversions.h"
+#include "chrome/browser/autocomplete/history_provider_util.h"
+#include "chrome/browser/history/url_database.h"
+#include "net/base/escape.h"
+#include "net/base/net_util.h"
+
+using base::Time;
+using base::TimeDelta;
+
 namespace history {
 
-InMemoryURLIndex::InMemoryURLIndex() {}
+ScoredHistoryMatch::ScoredHistoryMatch() : raw_score(0) {}
+
+ScoredHistoryMatch::ScoredHistoryMatch(const URLRow& url_info,
+                                       size_t input_location,
+                                       bool match_in_scheme,
+                                       bool innermost_match,
+                                       int score)
+    : HistoryMatch(url_info, input_location, match_in_scheme, innermost_match),
+      raw_score(score) {
+}
+
+InMemoryURLIndex::InMemoryURLIndex() : history_item_count_(0) {}
 
 InMemoryURLIndex::~InMemoryURLIndex() {}
 
+static const int32_t kURLToLowerBufferSize = 2048;
+
+// Indexing
+
+bool InMemoryURLIndex::Init(history::URLDatabase* history_db,
+                            const std::string& languages) {
+  // TODO(mrossetti): Register for profile/language change notifications.
+  languages_ = languages;
+  // Reset our indexes.
+  char_word_map_.clear();
+  word_id_history_map_.clear();
+  if (!history_db)
+    return false;
+  URLDatabase::URLEnumerator history_enum;
+  if (history_db->InitURLEnumeratorForEverything(&history_enum)) {
+    URLRow row;
+    Time recent_threshold = InMemoryURLIndex::RecentThreshold();
+    while (history_enum.GetNextURL(&row)) {
+      // Do some filtering so that we only get history items which could
+      // possibly pass the HistoryURLProvider::CullPoorMatches filter later.
+      if ((row.typed_count() > kLowQualityMatchTypedLimit) ||
+          (row.visit_count() > kLowQualityMatchVisitLimit) ||
+          (row.last_visit() >= recent_threshold)) {
+        if (!IndexRow(row))
+          return false;
+      }
+    }
+  }
+  return true;
+}
+
+bool InMemoryURLIndex::IndexRow(URLRow row) {
+  const GURL& gurl(row.url());
+  string16 url(net::FormatUrl(gurl, languages_,
+      net::kFormatUrlOmitUsernamePassword,
+      UnescapeRule::SPACES | UnescapeRule::URL_SPECIAL_CHARS,
+      NULL, NULL, NULL));
+
+  // TODO(mrossetti): Detect row_id > std::numeric_limits<HistoryID>::max().
+  HistoryID history_id = static_cast<HistoryID>(row.id());
+
+  // Add the row for quick lookup in the history info store.
+  url = l10n_util::ToLower(url);
+  URLRow new_row(GURL(url), row.id());
+  new_row.set_visit_count(row.visit_count());
+  new_row.set_typed_count(row.typed_count());
+  new_row.set_last_visit(row.last_visit());
+  new_row.set_title(row.title());
+  history_info_map_.insert(std::make_pair(history_id, new_row));
+
+  // Split into individual, unique words.
+  String16Set words = WordSetFromString16(url);
+
+  // For each word, add a new entry into the word index referring to the
+  // associated history item.
+  for (String16Set::iterator iter = words.begin();
+       iter != words.end(); ++iter) {
+    String16Set::value_type uni_word = *iter;
+    AddWordToIndex(uni_word, history_id);
+  }
+  ++history_item_count_;
+  return true;
+}
+
+// Searching
+
+ScoredHistoryMatches InMemoryURLIndex::HistoryItemsForTerms(
+    const String16Vector& terms) {
+  ScoredHistoryMatches scored_items;
+  if (!terms.empty()) {
+    // Reset used_ flags for term_char_word_set_cache_. We use a basic mark-
+    // and-sweep approach.
+    ResetTermCharWordSetCache();
+
+    // Lowercase the terms.
+    // TODO(mrossetti): Another opportunity for a transform algorithm.
+    String16Vector lower_terms;
+    for (String16Vector::const_iterator term_iter = terms.begin();
+         term_iter != terms.end(); ++term_iter) {
+      String16Vector::value_type lower_string(*term_iter);
+      std::transform(lower_string.begin(),
+                     lower_string.end(),
+                     lower_string.begin(),
+                     tolower);
+      lower_terms.push_back(lower_string);
+    }
+
+    String16Vector::value_type all_terms(JoinString(lower_terms, ' '));
+    HistoryIDSet history_id_set = HistoryIDSetFromWords(all_terms);
+
+    // Pass over all of the candidates filtering out any without a proper
+    // substring match, inserting those which pass in order by score.
+    scored_items = std::for_each(history_id_set.begin(), history_id_set.end(),
+                                 AddHistoryMatch(*this,
+                                                 lower_terms)).ScoredMatches();
+  }
+
+  // Remove any stale TermCharWordSet's.
+  term_char_word_set_cache_.erase(
+      std::remove_if(term_char_word_set_cache_.begin(),
+                     term_char_word_set_cache_.end(),
+                     std::mem_fun_ref(&TermCharWordSet::IsNotUsed)),
+      term_char_word_set_cache_.end());
+  return scored_items;
+}
+
+void InMemoryURLIndex::ResetTermCharWordSetCache() {
+  // TODO(mrossetti): Consider keeping more of the cache around for possible
+  // repeat searches, except a 'shortcuts' approach might be better for that.
+  // TODO(mrossetti): Change TermCharWordSet to a class and use for_each.
+  for (TermCharWordSetVector::iterator iter =
+       term_char_word_set_cache_.begin();
+       iter != term_char_word_set_cache_.end(); ++iter)
+    iter->used_ = false;
+}
+
+InMemoryURLIndex::HistoryIDSet InMemoryURLIndex::HistoryIDSetFromWords(
+    const string16& uni_string) {
+  // Break the terms down into individual terms (words), get the candidate
+  // set for each term, and intersect each to get a final candidate list.
+  // Note that a single 'term' from the user's perspective might be
+  // a string like "http://www.somewebsite.com" which, from our perspective,
+  // is four words: 'http', 'www', 'somewebsite', and 'com'.
+  HistoryIDSet history_id_set;
+  String16Set words = WordSetFromString16(uni_string);
+  bool first_word = true;
+  for (String16Set::iterator iter = words.begin();
+       iter != words.end(); ++iter) {
+    String16Set::value_type uni_word = *iter;
+    HistoryIDSet term_history_id_set =
+        InMemoryURLIndex::HistoryIDsForTerm(uni_word);
+    if (first_word) {
+      history_id_set.swap(term_history_id_set);
+      first_word = false;
+    } else {
+      HistoryIDSet old_history_id_set(history_id_set);
+      history_id_set.clear();
+      std::set_intersection(old_history_id_set.begin(),
+                            old_history_id_set.end(),
+                            term_history_id_set.begin(),
+                            term_history_id_set.end(),
+                            std::inserter(history_id_set,
+                                          history_id_set.begin()));
+    }
+  }
+  return history_id_set;
+}
+
+InMemoryURLIndex::HistoryIDSet InMemoryURLIndex::HistoryIDsForTerm(
+    const string16& uni_word) {
+  InMemoryURLIndex::HistoryIDSet history_id_set;
+
+  // For each character in the word, get the char/word_id map entry and
+  // intersect with the set in an incremental manner.
+  Char16Set uni_chars = CharactersFromString16(uni_word);
+  WordIDSet word_id_set(WordIDSetForTermChars(uni_chars));
+
+  // If any words resulted then we can compose a set of history IDs by unioning
+  // the sets from each word.
+  if (!word_id_set.empty()) {
+    for (WordIDSet::iterator word_id_iter = word_id_set.begin();
+         word_id_iter != word_id_set.end(); ++word_id_iter) {
+      WordID word_id = *word_id_iter;
+      WordIDHistoryMap::iterator word_iter = word_id_history_map_.find(word_id);
+      if (word_iter != word_id_history_map_.end()) {
+        HistoryIDSet& word_history_id_set(word_iter->second);
+        history_id_set.insert(word_history_id_set.begin(),
+                              word_history_id_set.end());
+      }
+    }
+  }
+
+  return history_id_set;
+}
+
+// Utility Functions
+
+// static
+InMemoryURLIndex::String16Set InMemoryURLIndex::WordSetFromString16(
+    const string16& uni_string) {
+  String16Set words;
+  WordIterator iter(&uni_string, WordIterator::BREAK_WORD);
+  if (iter.Init()) {
+    while (iter.Advance()) {
+      if (iter.IsWord())
+        words.insert(iter.GetWord());
+    }
+  }
+  return words;
+}
+
+// static
+InMemoryURLIndex::Char16Set InMemoryURLIndex::CharactersFromString16(
+    const string16& uni_word) {
+  Char16Set characters;
+  for (string16::const_iterator iter = uni_word.begin();
+       iter != uni_word.end(); ++iter)
+    characters.insert(*iter);
+  return characters;
+}
+
+void InMemoryURLIndex::AddWordToIndex(const string16& uni_word,
+                                      HistoryID history_id) {
+  WordMap::iterator word_pos = word_map_.find(uni_word);
+  if (word_pos != word_map_.end())
+    UpdateWordHistory(word_pos->second, history_id);
+  else
+    AddWordHistory(uni_word, history_id);
+}
+
+void InMemoryURLIndex::UpdateWordHistory(WordID word_id, HistoryID history_id) {
+    WordIDHistoryMap::iterator history_pos = word_id_history_map_.find(word_id);
+    DCHECK(history_pos != word_id_history_map_.end());
+    HistoryIDSet& history_id_set(history_pos->second);
+    history_id_set.insert(history_id);
+}
+
+// Add a new word to the word list and the word map, and then create a
+// new entry in the word/history map.
+void InMemoryURLIndex::AddWordHistory(const string16& uni_word,
+                                      HistoryID history_id) {
+  word_list_.push_back(uni_word);
+  WordID word_id = word_list_.size() - 1;
+  word_map_.insert(std::make_pair(uni_word, word_id));
+  HistoryIDSet history_id_set;
+  history_id_set.insert(history_id);
+  word_id_history_map_.insert(std::make_pair(word_id, history_id_set));
+  // For each character in the newly added word (i.e. a word that is not
+  // already in the word index), add the word to the character index.
+  Char16Set characters = CharactersFromString16(uni_word);
+  for (Char16Set::iterator uni_char_iter = characters.begin();
+       uni_char_iter != characters.end(); ++uni_char_iter) {
+    Char16Set::value_type uni_string = *uni_char_iter;
+    CharWordIDMap::iterator char_iter = char_word_map_.find(uni_string);
+    if (char_iter != char_word_map_.end()) {
+      // Update existing entry in the char/word index.
+      WordIDSet& word_id_set(char_iter->second);
+      word_id_set.insert(word_id);
+    } else {
+      // Create a new entry in the char/word index.
+      WordIDSet word_id_set;
+      word_id_set.insert(word_id);
+      char_word_map_.insert(std::make_pair(uni_string, word_id_set));
+    }
+  }
+}
+
+InMemoryURLIndex::WordIDSet InMemoryURLIndex::WordIDSetForTermChars(
+    InMemoryURLIndex::Char16Set const& uni_chars) {
+  TermCharWordSet* best_term_char_word_set = NULL;
+  bool set_found = false;
+  size_t outstanding_count = 0;
+  Char16Set outstanding_chars;
+  for (TermCharWordSetVector::iterator iter = term_char_word_set_cache_.begin();
+       iter != term_char_word_set_cache_.end(); ++iter) {
+    TermCharWordSetVector::value_type& term_char_word_set(*iter);
+    Char16Set& char_set(term_char_word_set.char_set_);
+    Char16Set exclusions;
+    std::set_difference(char_set.begin(), char_set.end(),
+                        uni_chars.begin(), uni_chars.end(),
+                        std::inserter(exclusions, exclusions.begin()));
+    if (exclusions.empty()) {
+      // Do a reverse difference so that we know which characters remain
+      // to be indexed. Then decide if this is a better match than any
+      // previous cached set.
+      std::set_difference(uni_chars.begin(), uni_chars.end(),
+                          char_set.begin(), char_set.end(),
+                          std::inserter(exclusions, exclusions.begin()));
+      if (!set_found || exclusions.size() < outstanding_count) {
+        outstanding_chars = exclusions;
+        best_term_char_word_set = &*iter;
+        outstanding_count = exclusions.size();
+        set_found = true;
+      }
+    }
+  }
+
+  WordIDSet word_id_set;
+  if (set_found && outstanding_count == 0) {
+    // If there were no oustanding characters then we can use the cached one.
+    best_term_char_word_set->used_ = true;
+    word_id_set = best_term_char_word_set->word_id_set_;
+  } else {
+    // Some or all of the characters remain to be indexed.
+    bool first_character = true;
+    if (set_found) {
+      first_character = false;
+      word_id_set = best_term_char_word_set->word_id_set_;
+    } else {
+      outstanding_chars = uni_chars;
+    }
+
+    for (Char16Set::iterator uni_char_iter = outstanding_chars.begin();
+         uni_char_iter != outstanding_chars.end(); ++uni_char_iter) {
+      Char16Set::value_type uni_char = *uni_char_iter;
+      CharWordIDMap::iterator char_iter = char_word_map_.find(uni_char);
+      if (char_iter == char_word_map_.end()) {
+        // The character was not found so bail.
+        word_id_set.clear();
+        break;
+      }
+      WordIDSet& char_word_id_set(char_iter->second);
+      if (first_character) {
+        word_id_set = char_word_id_set;
+        first_character = false;
+      } else {
+        WordIDSet old_word_id_set(word_id_set);
+        word_id_set.clear();
+        std::set_intersection(old_word_id_set.begin(),
+                              old_word_id_set.end(),
+                              char_word_id_set.begin(),
+                              char_word_id_set.end(),
+                              std::inserter(word_id_set,
+                              word_id_set.begin()));
+      }
+    }
+    // Update the cache.
+    if (!set_found || outstanding_count) {
+      term_char_word_set_cache_.push_back(TermCharWordSet(uni_chars,
+          word_id_set, true));
+    }
+  }
+  return word_id_set;
+}
+
+// static
+int InMemoryURLIndex::RawScoreForURL(const URLRow& row,
+                                     const String16Vector& terms,
+                                     size_t* first_term_location) {
+  GURL gurl = row.url();
+  if (!gurl.is_valid())
+    return 0;
+
+  string16 url = UTF8ToUTF16(gurl.spec());
+
+  // Collect all term start positions so we can see if they appear in order.
+  std::vector<size_t> term_locations;
+  int out_of_order = 0;  // Count the terms which are out of order.
+  size_t start_location_total = 0;
+  size_t term_length_total = 0;
+  for (String16Vector::const_iterator iter = terms.begin(); iter != terms.end();
+       ++iter) {
+    string16 term = *iter;
+    size_t term_location = url.find(term);
+    if (term_location == string16::npos)
+      return 0;  // A term was not found.  This should not happen.
+    if (iter != terms.begin()) {
+      // See if this term is out-of-order.
+      for (std::vector<size_t>::const_iterator order_iter =
+               term_locations.begin(); order_iter != term_locations.end();
+               ++order_iter) {
+        if (term_location <= *order_iter)
+          ++out_of_order;
+      }
+    } else {
+      *first_term_location = term_location;
+    }
+    term_locations.push_back(term_location);
+    start_location_total += term_location;
+    term_length_total += term.size();
+  }
+
+  // Calculate a raw score.
+  // TODO(mrossetti): This is good enough for now but must be fine-tuned.
+  const float kOrderMaxValue = 10.0;
+  float order_value = 10.0;
+  if (terms.size() > 1) {
+    int max_possible_out_of_order = (terms.size() * (terms.size() - 1)) / 2;
+    order_value =
+        (static_cast<float>(max_possible_out_of_order - out_of_order) /
+         max_possible_out_of_order) * kOrderMaxValue;
+  }
+
+  const float kStartMaxValue = 10.0;
+  const size_t kMaxSignificantStart = 20;
+  float start_value =
+      (static_cast<float>(kMaxSignificantStart -
+       std::min(kMaxSignificantStart, start_location_total / terms.size()))) /
+      static_cast<float>(kMaxSignificantStart) * kStartMaxValue;
+
+  const float kCompleteMaxValue = 10.0;
+  float complete_value =
+      (static_cast<float>(term_length_total) / static_cast<float>(url.size())) *
+      kStartMaxValue;
+
+  const float kLastVisitMaxValue = 10.0;
+  const base::TimeDelta kMaxSignificantDay = base::TimeDelta::FromDays(30);
+  int64 delta_time = (kMaxSignificantDay -
+      std::min((base::Time::Now() - row.last_visit()),
+               kMaxSignificantDay)).ToInternalValue();
+  float last_visit_value =
+      (static_cast<float>(delta_time) /
+       static_cast<float>(kMaxSignificantDay.ToInternalValue())) *
+      kLastVisitMaxValue;
+
+  const float kVisitCountMaxValue = 10.0;
+  const int kMaxSignificantVisits = 10;
+  float visit_count_value =
+      (static_cast<float>(std::min(row.visit_count(),
+       kMaxSignificantVisits))) / static_cast<float>(kMaxSignificantVisits) *
+      kVisitCountMaxValue;
+  float raw_score = order_value + start_value + complete_value +
+      last_visit_value + visit_count_value;
+
+  // Normalize the score.
+  const float kMaxNormalizedRawScore = 1000.0;
+  raw_score =
+      (raw_score / (kOrderMaxValue + kStartMaxValue + kCompleteMaxValue +
+                    kLastVisitMaxValue + kVisitCountMaxValue)) *
+      kMaxNormalizedRawScore;
+  return static_cast<int>(raw_score);
+}
+
+// static
+Time InMemoryURLIndex::RecentThreshold() {
+  return Time::Now() - TimeDelta::FromDays(kLowQualityMatchAgeLimitInDays);
+}
+
+void InMemoryURLIndex::AddHistoryMatch::operator()(
+    const InMemoryURLIndex::HistoryID history_id) {
+  HistoryInfoMap::const_iterator hist_pos =
+      index_.history_info_map_.find(history_id);
+  if (hist_pos != index_.history_info_map_.end()) {
+    const URLRow& hist_item = hist_pos->second;
+    // TODO(mrossetti): Accommodate multiple term highlighting.
+    size_t input_location = 0;
+    int score = InMemoryURLIndex::RawScoreForURL(
+        hist_item, lower_terms_, &input_location);
+    if (score != 0) {
+      // We only retain the top 10 highest scoring results so
+      // see if this one fits into the top 10 and, if so, where.
+      ScoredHistoryMatches::iterator scored_iter = scored_matches_.begin();
+      while (scored_iter != scored_matches_.end() &&
+             (*scored_iter).raw_score > score)
+        ++scored_iter;
+      if ((scored_matches_.size() < 10) ||
+          (scored_iter != scored_matches_.end())) {
+        // Create and insert the new item.
+        // TODO(mrossetti): Properly set |match_in_scheme| and
+        // |innermost_match|.
+        bool match_in_scheme = false;
+        bool innermost_match = true;
+        ScoredHistoryMatch match(hist_item, input_location,
+            match_in_scheme, innermost_match, score);
+        if (!scored_matches_.empty())
+          scored_matches_.insert(scored_iter, match);
+        else
+          scored_matches_.push_back(match);
+        // Trim any entries beyond 10.
+        if (scored_matches_.size() > 10) {
+          scored_matches_.erase(scored_matches_.begin() + 10,
+                                scored_matches_.end());
+        }
+      }
+    }
+  }
+}
+
 }  // namespace history
diff --git a/chrome/browser/history/in_memory_url_index.h b/chrome/browser/history/in_memory_url_index.h
index 7b57a4a..b5b3373 100644
--- a/chrome/browser/history/in_memory_url_index.h
+++ b/chrome/browser/history/in_memory_url_index.h
@@ -4,18 +4,238 @@
 
 #ifndef CHROME_BROWSER_HISTORY_IN_MEMORY_URL_INDEX_H_
 #define CHROME_BROWSER_HISTORY_IN_MEMORY_URL_INDEX_H_
+#pragma once
+
+#include <functional>
+#include <map>
+#include <set>
+#include <string>
+#include <vector>
+
+#include "app/sql/connection.h"
+#include "base/basictypes.h"
+#include "base/linked_ptr.h"
+#include "base/scoped_ptr.h"
+#include "base/string16.h"
+#include "chrome/browser/autocomplete/history_provider_util.h"
+#include "chrome/browser/history/history_types.h"
+#include "testing/gtest/include/gtest/gtest_prod.h"
+
+namespace base {
+class Time;
+}
 
 namespace history {
 
+class URLDatabase;
+
+// Used for intermediate history result operations.
+struct ScoredHistoryMatch : public HistoryMatch {
+  // Required for STL, we don't use this directly.
+  ScoredHistoryMatch();
+
+  ScoredHistoryMatch(const URLRow& url_info,
+                     size_t input_location,
+                     bool match_in_scheme,
+                     bool innermost_match,
+                     int score);
+
+  // An interim score taking into consideration location and completeness
+  // of the match.
+  int raw_score;
+};
+typedef std::vector<ScoredHistoryMatch> ScoredHistoryMatches;
+
 // The URL history source.
 // Holds portions of the URL database in memory in an indexed form.  Used to
 // quickly look up matching URLs for a given query string.  Used by
 // the HistoryURLProvider for inline autocomplete and to provide URL
 // matches to the omnibox.
+//
+// Note about multi-byte codepoints and the data structures in the
+// InMemoryURLIndex class: One will quickly notice that no effort is made to
+// insure that multi-byte character boundaries are detected when indexing the
+// words and characters in the URL history database except when converting
+// URL strings to lowercase. Multi-byte-edness makes no difference when
+// indexing or when searching the index as the final filtering of results
+// is dependent on the comparison of a string of bytes, not individual
+// characters. While the lookup of those bytes during a search in the
+// |char_word_map_| could serve up words in which the individual char16
+// occurs as a portion of a composite character the next filtering step
+// will eliminate such words except in the case where a single character
+// is being searched on and which character occurs as the second char16 of a
+// multi-char16 instance.
 class InMemoryURLIndex {
  public:
   InMemoryURLIndex();
   ~InMemoryURLIndex();
+
+  // Convenience types
+  typedef std::vector<string16> String16Vector;
+
+  // Open and index the URL history database.
+  bool Init(URLDatabase* history_db, const std::string& languages);
+
+  // Reset the history index.
+  void Reset();
+
+  // Given a vector containing one or more words as string16s, scan the
+  // history index and return a vector with all scored, matching history items.
+  // Each term must occur somewhere in the history item for the item to
+  // qualify; however, the terms do not necessarily have to be adjacent.
+  // Results are sorted with higher scoring items first.
+  ScoredHistoryMatches HistoryItemsForTerms(const String16Vector& terms);
+
+  // Returns the date threshold for considering an history item as significant.
+  static base::Time RecentThreshold();
+
+ private:
+  friend class AddHistoryMatch;
+  friend class InMemoryURLIndexTest;
+  FRIEND_TEST(InMemoryURLIndexTest, Initialization);
+
+  // Convenience types.
+  typedef std::set<string16> String16Set;
+  typedef std::set<char16> Char16Set;
+
+  // An index into list of all of the words we have indexed.
+  typedef int16 WordID;
+
+  // A map allowing a WordID to be determined given a word.
+  typedef std::map<string16, WordID> WordMap;
+
+  // A map from character to word_ids.
+  typedef std::set<WordID> WordIDSet;  // An index into the WordList.
+  typedef std::map<char16, WordIDSet> CharWordIDMap;
+
+  // A map from word_id to history item.
+  // TODO(mrossetti): URLID is 64 bit: a memory bloat and performance hit.
+  // Consider using a smaller type.
+  typedef URLID HistoryID;
+  typedef std::set<HistoryID> HistoryIDSet;
+  typedef std::map<WordID, HistoryIDSet> WordIDHistoryMap;
+
+  // Support caching of term character intersections so that we can optimize
+  // searches which build upon a previous search.
+  struct TermCharWordSet {
+    TermCharWordSet(Char16Set char_set, WordIDSet word_id_set, bool used)
+        : char_set_(char_set),
+          word_id_set_(word_id_set),
+          used_(used) {}
+
+    bool IsNotUsed() const { return !used_; }
+
+    Char16Set char_set_;
+    WordIDSet word_id_set_;
+    bool used_;  // true if this set has been used for the current term search.
+  };
+  typedef std::vector<TermCharWordSet> TermCharWordSetVector;
+
+  // TODO(rohitrao): Probably replace this with QueryResults.
+  typedef std::vector<URLRow> URLRowVector;
+
+  // A map from history_id to the history's URL and title.
+  typedef std::map<HistoryID, URLRow> HistoryInfoMap;
+
+  // A helper class which performs the final filter on each candidate
+  // history URL match, inserting accepted matches into |scored_matches_|
+  // and trimming the maximum number of matches to 10.
+  class AddHistoryMatch : std::unary_function<HistoryID, void> {
+   public:
+    AddHistoryMatch(const InMemoryURLIndex& index,
+                    const String16Vector& lower_terms)
+        : index_(index),
+          lower_terms_(lower_terms) {}
+
+    void operator()(const HistoryID history_id);
+
+    ScoredHistoryMatches ScoredMatches() const { return scored_matches_; }
+
+   private:
+    const InMemoryURLIndex& index_;
+    ScoredHistoryMatches scored_matches_;
+    const String16Vector& lower_terms_;
+  };
+
+  // Break a string down into individual words.
+  static String16Set WordSetFromString16(const string16& uni_string);
+
+  // Given a set of Char16s, find words containing those characters. If any
+  // existing, cached set is a proper subset then start with that cached
+  // set. Update the cache.
+  WordIDSet WordIDSetForTermChars(const Char16Set& uni_chars);
+
+  // URL History indexing support functions.
+
+  // Index one URL history item.
+  bool IndexRow(URLRow row);
+
+  // Break a string down into its individual characters.
+  // Note that this is temporarily intended to work on a single word, but
+  // _will_ work on a string of words, perhaps with unexpected results.
+  // TODO(mrossetti): Lots of optimizations possible here for not restarting
+  // a search if the user is just typing along. Also, change this to uniString
+  // and properly handle substring matches, scoring and sorting the results
+  // by score. Also, provide the metrics for where the matches occur so that
+  // the UI can highlight the matched sections.
+  Char16Set CharactersFromString16(const string16& uni_word);
+
+  // Given a single word, add a reference to the containing history item
+  // to the index.
+  void AddWordToIndex(const string16& uni_word, HistoryID history_id);
+
+  // Update an existing entry in the word/history index by adding the
+  // |history_id| to set for |word_id| in the word_id_history_map_.
+  void UpdateWordHistory(WordID word_id, HistoryID history_id);
+
+  // Create a new entry in the word/history map for |word_id| and add
+  // |history_id| as the initial element of the word's set.
+  void AddWordHistory(const string16& uni_word, HistoryID history_id);
+
+  // Clear the search term cache. This cache holds on to the intermediate
+  // word results for each previously typed character to eliminate the need
+  // to re-perform set operations for previously typed characters.
+  void ResetTermCharWordSetCache();
+
+  // Compose a set of history item IDs by intersecting the set for each word
+  // in |uni_string|.
+  HistoryIDSet HistoryIDSetFromWords(const string16& uni_string);
+
+  // Helper function to HistoryIDSetFromWords which composes a set of history
+  // ids for the given term given in |uni_word|.
+  HistoryIDSet HistoryIDsForTerm(const string16& uni_word);
+
+  // Calculate a raw score for this history item by first determining
+  // if all of the terms in |terms_vector| occur in |row| and, if so,
+  // calculating a raw score based on 1) starting position of each term
+  // in the user input, 2) completeness of each term's match, 3) ordering
+  // of the occurrence of each term (i.e. they appear in order), 4) last
+  // visit time, and 5) number of visits.
+  // This raw score allows the results to be ordered and can be used
+  // to influence the final score calculated by the client of this
+  // index. Return the starting location of the first term in
+  // |first_term_location|.
+  static int RawScoreForURL(const URLRow& row,
+                            const String16Vector& terms_vector,
+                            size_t* first_term_location);
+
+  // A list of all of indexed words. The index of a word in this list is the
+  // ID of the word in the word_map_. It reduces the memory overhead by
+  // replacing a potentially long and repeated string with a simple index.
+  // NOTE: A word will _never_ be removed from this vector thus insuring
+  // the immutability of the word_id throughout the session, reducing
+  // maintenance complexity.
+  String16Vector word_list_;
+
+  uint64 history_item_count_;
+  WordMap word_map_;
+  CharWordIDMap char_word_map_;
+  WordIDHistoryMap word_id_history_map_;
+  TermCharWordSetVector term_char_word_set_cache_;
+  HistoryInfoMap history_info_map_;
+  std::string languages_;
+
+  DISALLOW_COPY_AND_ASSIGN(InMemoryURLIndex);
 };
 
 }  // namespace history
diff --git a/chrome/browser/history/in_memory_url_index_unittest.cc b/chrome/browser/history/in_memory_url_index_unittest.cc
index f5932ef..9306ec5 100644
--- a/chrome/browser/history/in_memory_url_index_unittest.cc
+++ b/chrome/browser/history/in_memory_url_index_unittest.cc
@@ -2,15 +2,105 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "chrome/browser/history/in_memory_url_index.h"
+#include <stdio.h>
+
+#include <fstream>
+#include <string>
+#include <vector>
 
+#include "app/sql/connection.h"
+#include "app/sql/statement.h"
+#include "app/sql/transaction.h"
+#include "base/file_util.h"
+#include "base/path_service.h"
 #include "base/scoped_ptr.h"
+#include "base/time.h"
+#include "base/utf_string_conversions.h"
+#include "chrome/browser/history/in_memory_url_index.h"
+#include "chrome/browser/history/in_memory_database.h"
+#include "chrome/common/chrome_paths.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
+// The test version of the history url database table ('url') is contained in
+// a database file created from a text file('url_history_provider_test.db.txt').
+// The only difference between this table and a live 'urls' table from a
+// profile is that the last_visit_time column in the test table contains a
+// number specifying the number of days relative to 'today' to which the
+// absolute time should be set during the test setup stage.
+//
+// The format of the test database text file is of a SQLite .dump file.
+// Note that only lines whose first character is an upper-case letter are
+// processed when creating the test database.
+
+using base::Time;
+using base::TimeDelta;
+
 namespace history {
 
-class InMemoryURLIndexTest : public testing::Test {
+class InMemoryURLIndexTest : public testing::Test,
+                             public InMemoryDatabase {
+ public:
+  InMemoryURLIndexTest() { InitFromScratch(); }
+
  protected:
+  // Test setup.
+  virtual void SetUp() {
+    // Create and populate a working copy of the URL history database.
+    FilePath history_proto_path;
+    PathService::Get(chrome::DIR_TEST_DATA, &history_proto_path);
+    history_proto_path = history_proto_path.Append(
+        FILE_PATH_LITERAL("History"));
+    history_proto_path = history_proto_path.Append(
+        FILE_PATH_LITERAL("url_history_provider_test.db.txt"));
+    EXPECT_TRUE(file_util::PathExists(history_proto_path));
+
+    std::ifstream proto_file(history_proto_path.value().c_str());
+    static const size_t kCommandBufferMaxSize = 2048;
+    char sql_cmd_line[kCommandBufferMaxSize];
+
+    sql::Connection& db(GetDB());
+    {
+      sql::Transaction transaction(&db);
+      transaction.Begin();
+      while (!proto_file.eof()) {
+        proto_file.getline(sql_cmd_line, kCommandBufferMaxSize);
+        if (!proto_file.eof()) {
+          // We only process lines which begin with a upper-case letter.
+          // TODO(mrossetti): Can iswupper() be used here?
+          if (sql_cmd_line[0] >= 'A' && sql_cmd_line[0] <= 'Z') {
+            std::string sql_cmd(sql_cmd_line);
+            sql::Statement sql_stmt(db.GetUniqueStatement(sql_cmd_line));
+            EXPECT_TRUE(sql_stmt.Run());
+          }
+        }
+      }
+      transaction.Commit();
+    }
+    proto_file.close();
+
+    // Update the last_visit_time table column
+    // such that it represents a time relative to 'now'.
+    sql::Statement statement(db.GetUniqueStatement(
+        "SELECT" HISTORY_URL_ROW_FIELDS "FROM urls;"));
+    EXPECT_TRUE(statement);
+    Time time_right_now = Time::NowFromSystemTime();
+    TimeDelta  day_delta = TimeDelta::FromDays(1);
+    {
+      sql::Transaction transaction(&db);
+      transaction.Begin();
+      while (statement.Step()) {
+        URLRow row;
+        FillURLRow(statement, &row);
+        Time last_visit = time_right_now;
+        for (int64 i = row.last_visit().ToInternalValue(); i > 0; --i)
+          last_visit -= day_delta;
+        row.set_last_visit(last_visit);
+        UpdateURLRow(row.id(), row);
+      }
+      transaction.Commit();
+    }
+  }
+
   scoped_ptr<InMemoryURLIndex> url_index_;
 };
 
@@ -19,4 +109,76 @@ TEST_F(InMemoryURLIndexTest, Construction) {
   EXPECT_TRUE(url_index_.get());
 }
 
+// TODO(mrossetti): Write python script to calculate the validation criteria.
+TEST_F(InMemoryURLIndexTest, Initialization) {
+  // Verify that the database contains the expected number of items, which
+  // is the pre-filtered count, i.e. all of the items.
+  sql::Statement statement(GetDB().GetUniqueStatement("SELECT * FROM urls;"));
+  EXPECT_TRUE(statement);
+  uint64 row_count = 0;
+  while (statement.Step()) ++row_count;
+  EXPECT_EQ(33U, row_count);
+  url_index_.reset(new InMemoryURLIndex);
+  url_index_->Init(this, "en,ja,hi,zh");
+
+  // There should have been 27 of the 31 urls accepted during filtering.
+  EXPECT_EQ(28U, url_index_->history_item_count_);
+
+  // history_info_map_ should have the same number of items as were filtered.
+  EXPECT_EQ(28U, url_index_->history_info_map_.size());
+
+  // The resulting indexes should account for:
+  //    37 characters
+  //    88 words
+  EXPECT_EQ(37U, url_index_->char_word_map_.size());
+  EXPECT_EQ(91U, url_index_->word_map_.size());
+}
+
+TEST_F(InMemoryURLIndexTest, Retrieval) {
+  url_index_.reset(new InMemoryURLIndex);
+  std::string languages("en,ja,hi,zh");
+  url_index_->Init(this, languages);
+  InMemoryURLIndex::String16Vector terms;
+  // The term will be lowercased by the search.
+
+  // See if a very specific term gives a single result.
+  string16 term = ASCIIToUTF16("DrudgeReport");
+  terms.push_back(term);
+  ScoredHistoryMatches matches = url_index_->HistoryItemsForTerms(terms);
+  EXPECT_EQ(1U, matches.size());
+
+  // Search which should result in multiple results.
+  terms.clear();
+  term = ASCIIToUTF16("drudge");
+  terms.push_back(term);
+  matches = url_index_->HistoryItemsForTerms(terms);
+  ASSERT_EQ(2U, matches.size());
+  // The results should be in descending score order.
+  EXPECT_GT(matches[0].raw_score, matches[1].raw_score);
+
+  // Search which should result in nearly perfect result.
+  terms.clear();
+  term = ASCIIToUTF16("http");
+  terms.push_back(term);
+  term = ASCIIToUTF16("NearlyPerfectResult");
+  terms.push_back(term);
+  matches = url_index_->HistoryItemsForTerms(terms);
+  ASSERT_EQ(1U, matches.size());
+  // The results should have a very high score.
+  EXPECT_GT(matches[0].raw_score, 900);
+
+  // Search which should result in very poor result.
+  terms.clear();
+  term = ASCIIToUTF16("z");
+  terms.push_back(term);
+  term = ASCIIToUTF16("y");
+  terms.push_back(term);
+  term = ASCIIToUTF16("x");
+  terms.push_back(term);
+  matches = url_index_->HistoryItemsForTerms(terms);
+  ASSERT_EQ(1U, matches.size());
+  // The results should have a poor score.
+  EXPECT_LT(matches[0].raw_score, 200);
+}
+
 }  // namespace history
diff --git a/chrome/browser/history/multipart_uitest.cc b/chrome/browser/history/multipart_uitest.cc
index a8fcf4c..036cd96 100644
--- a/chrome/browser/history/multipart_uitest.cc
+++ b/chrome/browser/history/multipart_uitest.cc
@@ -6,32 +6,39 @@
 
 #include "app/sql/connection.h"
 #include "app/sql/statement.h"
+#include "base/file_util.h"
 #include "chrome/test/automation/tab_proxy.h"
 #include "chrome/test/automation/browser_proxy.h"
-#include "net/url_request/url_request_unittest.h"
+#include "net/test/test_server.h"
 
 namespace {
 
 class MultipartResponseUITest : public UITest {
 };
 
+// http://crbug.com/50060
+#if defined(OS_MACOSX)
+#define MAYBE_SingleVisit DISABLED_SingleVisit
+#else
+#define MAYBE_SingleVisit SingleVisit
+#endif
+
 #if defined(NDEBUG)
 // http://code.google.com/p/chromium/issues/detail?id=37746
 // Running this test only for release builds as it fails in debug test
 // runs
-TEST_F(MultipartResponseUITest, SingleVisit) {
+TEST_F(MultipartResponseUITest, MAYBE_SingleVisit) {
   // Make sure that visiting a multipart/x-mixed-replace site only
   // creates one entry in the visits table.
-  const wchar_t kDocRoot[] = L"chrome/test/data";
-  scoped_refptr<HTTPTestServer> server =
-      HTTPTestServer::CreateServer(kDocRoot, NULL);
-  ASSERT_TRUE(NULL != server.get());
+  net::TestServer test_server(net::TestServer::TYPE_HTTP,
+                              FilePath(FILE_PATH_LITERAL("chrome/test/data")));
+  ASSERT_TRUE(test_server.Start());
 
   scoped_refptr<BrowserProxy> browser_proxy(automation()->GetBrowserWindow(0));
   ASSERT_TRUE(browser_proxy.get());
   scoped_refptr<TabProxy> tab_proxy(browser_proxy->GetActiveTab());
   ASSERT_TRUE(tab_proxy.get());
-  NavigateToURL(server->TestServerPage("multipart"));
+  NavigateToURL(test_server.GetURL("multipart"));
   std::wstring title;
   EXPECT_TRUE(tab_proxy->GetTabTitle(&title));
   EXPECT_EQ(L"page 9", title);
@@ -47,7 +54,8 @@ TEST_F(MultipartResponseUITest, SingleVisit) {
   ASSERT_TRUE(db.Open(history));
   std::string query(
       "SELECT COUNT(1) FROM visits, urls WHERE visits.url = urls.id"
-      " AND urls.url LIKE 'http://localhost:%/multipart'");
+      " AND urls.url LIKE 'http://" +
+      test_server.host_port_pair().HostForURL() + ":%/multipart'");
   {
     sql::Statement statement(db.GetUniqueStatement(query.c_str()));
     EXPECT_TRUE(statement);
diff --git a/chrome/browser/history/page_usage_data.h b/chrome/browser/history/page_usage_data.h
index 66a63e2..b7a689a 100644
--- a/chrome/browser/history/page_usage_data.h
+++ b/chrome/browser/history/page_usage_data.h
@@ -4,6 +4,7 @@
 
 #ifndef CHROME_BROWSER_HISTORY_PAGE_USAGE_DATA_H__
 #define CHROME_BROWSER_HISTORY_PAGE_USAGE_DATA_H__
+#pragma once
 
 #include "base/string16.h"
 #include "chrome/browser/history/history_types.h"
diff --git a/chrome/browser/history/query_parser.h b/chrome/browser/history/query_parser.h
index 8399abf..4b44c91 100644
--- a/chrome/browser/history/query_parser.h
+++ b/chrome/browser/history/query_parser.h
@@ -7,6 +7,7 @@
 
 #ifndef CHROME_BROWSER_HISTORY_QUERY_PARSER_H_
 #define CHROME_BROWSER_HISTORY_QUERY_PARSER_H_
+#pragma once
 
 #include <vector>
 
diff --git a/chrome/browser/history/redirect_uitest.cc b/chrome/browser/history/redirect_uitest.cc
index f7a1669..458c8e0 100644
--- a/chrome/browser/history/redirect_uitest.cc
+++ b/chrome/browser/history/redirect_uitest.cc
@@ -12,25 +12,35 @@
 #include "base/scoped_ptr.h"
 #include "base/string_util.h"
 #include "base/string16.h"
+#include "base/utf_string_conversions.h"
+#include "chrome/browser/view_ids.h"
+#include "chrome/test/automation/browser_proxy.h"
 #include "chrome/test/automation/tab_proxy.h"
+#include "chrome/test/automation/window_proxy.h"
 #include "chrome/test/ui/ui_test.h"
 #include "net/base/net_util.h"
-#include "net/url_request/url_request_unittest.h"
+#include "net/test/test_server.h"
+#include "views/event.h"
 
 namespace {
 
-const wchar_t kDocRoot[] = L"chrome/test/data";
+class RedirectTest : public UITest {
+ public:
+  RedirectTest()
+      : test_server_(net::TestServer::TYPE_HTTP,
+                     FilePath(FILE_PATH_LITERAL("chrome/test/data"))) {
+  }
 
-typedef UITest RedirectTest;
+ protected:
+  net::TestServer test_server_;
+};
 
 // Tests a single server redirect
 TEST_F(RedirectTest, Server) {
-  scoped_refptr<HTTPTestServer> server =
-    HTTPTestServer::CreateServer(kDocRoot, NULL);
-  ASSERT_TRUE(NULL != server.get());
+  ASSERT_TRUE(test_server_.Start());
 
-  GURL final_url = server->TestServerPage(std::string());
-  GURL first_url = server->TestServerPage(
+  GURL final_url = test_server_.GetURL(std::string());
+  GURL first_url = test_server_.GetURL(
       "server-redirect?" + final_url.spec());
 
   NavigateToURL(first_url);
@@ -46,13 +56,12 @@ TEST_F(RedirectTest, Server) {
 }
 
 // Tests a single client redirect.
-TEST_F(RedirectTest, Client) {
-  scoped_refptr<HTTPTestServer> server =
-    HTTPTestServer::CreateServer(kDocRoot, NULL);
-  ASSERT_TRUE(NULL != server.get());
+// Flaky: see crbug.com/55380
+TEST_F(RedirectTest, FLAKY_Client) {
+  ASSERT_TRUE(test_server_.Start());
 
-  GURL final_url = server->TestServerPage(std::string());
-  GURL first_url = server->TestServerPage(
+  GURL final_url = test_server_.GetURL(std::string());
+  GURL first_url = test_server_.GetURL(
       "client-redirect?" + final_url.spec());
 
   // The client redirect appears as two page visits in the browser.
@@ -81,11 +90,9 @@ TEST_F(RedirectTest, Client) {
 }
 
 TEST_F(RedirectTest, ClientEmptyReferer) {
-  scoped_refptr<HTTPTestServer> server =
-    HTTPTestServer::CreateServer(kDocRoot, NULL);
-  ASSERT_TRUE(NULL != server.get());
+  ASSERT_TRUE(test_server_.Start());
 
-  GURL final_url = server->TestServerPage(std::string());
+  GURL final_url = test_server_.GetURL(std::string());
   FilePath test_file(test_data_directory_);
   test_file = test_file.AppendASCII("file_client_redirect.html");
   GURL first_url = net::FilePathToFileURL(test_file);
@@ -103,7 +110,17 @@ TEST_F(RedirectTest, ClientEmptyReferer) {
 
 // Tests to make sure a location change when a pending redirect exists isn't
 // flagged as a redirect.
-TEST_F(RedirectTest, ClientCancelled) {
+#if defined(OS_MACOSX)
+// SimulateOSClick is broken on the Mac: http://crbug.com/45162
+#define MAYBE_ClientCancelled DISABLED_ClientCancelled
+#elif defined(OS_WIN)
+// http://crbug.com/53091
+#define MAYBE_ClientCancelled FAILS_ClientCancelled
+#else
+#define MAYBE_ClientCancelled ClientCancelled
+#endif
+
+TEST_F(RedirectTest, MAYBE_ClientCancelled) {
   FilePath first_path(test_data_directory_);
   first_path = first_path.AppendASCII("cancelled_redirect_test.html");
   ASSERT_TRUE(file_util::AbsolutePath(&first_path));
@@ -111,10 +128,26 @@ TEST_F(RedirectTest, ClientCancelled) {
 
   NavigateToURLBlockUntilNavigationsComplete(first_url, 1);
 
-  NavigateToURL(GURL("javascript:click()")); // User initiated location change.
-
+  scoped_refptr<BrowserProxy> browser = automation()->GetBrowserWindow(0);
+  ASSERT_TRUE(browser.get());
+  scoped_refptr<WindowProxy> window = browser->GetWindow();
+  ASSERT_TRUE(window.get());
   scoped_refptr<TabProxy> tab_proxy(GetActiveTab());
   ASSERT_TRUE(tab_proxy.get());
+  int64 last_nav_time = 0;
+  EXPECT_TRUE(tab_proxy->GetLastNavigationTime(&last_nav_time));
+  // Simulate a click to force to make a user-initiated location change;
+  // otherwise, a non user-initiated in-page location change will be treated
+  // as client redirect and the redirect will be recoreded, which can cause
+  // this test failed.
+  gfx::Rect tab_view_bounds;
+  ASSERT_TRUE(browser->BringToFront());
+  ASSERT_TRUE(window->GetViewBounds(VIEW_ID_TAB_CONTAINER, &tab_view_bounds,
+                                    true));
+  ASSERT_TRUE(
+      window->SimulateOSClick(tab_view_bounds.CenterPoint(),
+                              views::Event::EF_LEFT_BUTTON_DOWN));
+  EXPECT_TRUE(tab_proxy->WaitForNavigation(last_nav_time));
 
   std::vector<GURL> redirects;
   ASSERT_TRUE(tab_proxy->GetRedirectsFrom(first_url, &redirects));
@@ -141,16 +174,14 @@ TEST_F(RedirectTest, ClientCancelled) {
 
 // Tests a client->server->server redirect
 TEST_F(RedirectTest, ClientServerServer) {
-  scoped_refptr<HTTPTestServer> server =
-      HTTPTestServer::CreateServer(kDocRoot, NULL);
-  ASSERT_TRUE(NULL != server.get());
+  ASSERT_TRUE(test_server_.Start());
 
-  GURL final_url = server->TestServerPage(std::string());
-  GURL next_to_last = server->TestServerPage(
+  GURL final_url = test_server_.GetURL(std::string());
+  GURL next_to_last = test_server_.GetURL(
       "server-redirect?" + final_url.spec());
-  GURL second_url = server->TestServerPage(
+  GURL second_url = test_server_.GetURL(
       "server-redirect?" + next_to_last.spec());
-  GURL first_url = server->TestServerPage(
+  GURL first_url = test_server_.GetURL(
       "client-redirect?" + second_url.spec());
   std::vector<GURL> redirects;
 
@@ -175,14 +206,12 @@ TEST_F(RedirectTest, ClientServerServer) {
 
 // Tests that the "#reference" gets preserved across server redirects.
 TEST_F(RedirectTest, ServerReference) {
-  scoped_refptr<HTTPTestServer> server =
-    HTTPTestServer::CreateServer(kDocRoot, NULL);
-  ASSERT_TRUE(NULL != server.get());
+  ASSERT_TRUE(test_server_.Start());
 
   const std::string ref("reference");
 
-  GURL final_url = server->TestServerPage(std::string());
-  GURL initial_url = server->TestServerPage(
+  GURL final_url = test_server_.GetURL(std::string());
+  GURL initial_url = test_server_.GetURL(
       "server-redirect?" + final_url.spec() + "#" + ref);
 
   NavigateToURL(initial_url);
@@ -195,14 +224,12 @@ TEST_F(RedirectTest, ServerReference) {
 // A) does not crash the browser or confuse the redirect chain, see bug 1080873
 // B) does not take place.
 TEST_F(RedirectTest, NoHttpToFile) {
-  scoped_refptr<HTTPTestServer> server =
-      HTTPTestServer::CreateServer(kDocRoot, NULL);
-  ASSERT_TRUE(NULL != server.get());
+  ASSERT_TRUE(test_server_.Start());
   FilePath test_file(test_data_directory_);
   test_file = test_file.AppendASCII("http_to_file.html");
   GURL file_url = net::FilePathToFileURL(test_file);
 
-  GURL initial_url = server->TestServerPage(
+  GURL initial_url = test_server_.GetURL(
       "client-redirect?" + file_url.spec());
 
   NavigateToURL(initial_url);
@@ -218,9 +245,7 @@ TEST_F(RedirectTest, NoHttpToFile) {
 // Ensures that non-user initiated location changes (within page) are
 // flagged as client redirects. See bug 1139823.
 TEST_F(RedirectTest, ClientFragments) {
-  scoped_refptr<HTTPTestServer> server =
-    HTTPTestServer::CreateServer(kDocRoot, NULL);
-  ASSERT_TRUE(NULL != server.get());
+  ASSERT_TRUE(test_server_.Start());
 
   FilePath test_file(test_data_directory_);
   test_file = test_file.AppendASCII("ref_redirect.html");
@@ -252,13 +277,11 @@ TEST_F(RedirectTest,
   // which causes it to start a provisional load, and while it is waiting
   // for the response (which means it hasn't committed the load for the client
   // redirect destination page yet), we issue a new navigation request.
-  scoped_refptr<HTTPTestServer> server =
-    HTTPTestServer::CreateServer(kDocRoot, NULL);
-  ASSERT_TRUE(NULL != server.get());
+  ASSERT_TRUE(test_server_.Start());
 
-  GURL final_url = server->TestServerPage("files/title2.html");
-  GURL slow = server->TestServerPage("slow?60");
-  GURL first_url = server->TestServerPage(
+  GURL final_url = test_server_.GetURL("files/title2.html");
+  GURL slow = test_server_.GetURL("slow?60");
+  GURL first_url = test_server_.GetURL(
       "client-redirect?" + slow.spec());
   std::vector<GURL> redirects;
 
diff --git a/chrome/browser/history/snippet.cc b/chrome/browser/history/snippet.cc
index cb96e16..6e3e93c 100644
--- a/chrome/browser/history/snippet.cc
+++ b/chrome/browser/history/snippet.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -8,6 +8,7 @@
 
 #include "base/logging.h"
 #include "base/scoped_ptr.h"
+#include "base/string_split.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
 #include "unicode/brkiter.h"
diff --git a/chrome/browser/history/snippet.h b/chrome/browser/history/snippet.h
index 9e92893..ffa8fa1 100644
--- a/chrome/browser/history/snippet.h
+++ b/chrome/browser/history/snippet.h
@@ -7,6 +7,7 @@
 
 #ifndef CHROME_BROWSER_HISTORY_SNIPPET_H__
 #define CHROME_BROWSER_HISTORY_SNIPPET_H__
+#pragma once
 
 #include <vector>
 
diff --git a/chrome/browser/history/snippet_unittest.cc b/chrome/browser/history/snippet_unittest.cc
index 5bc8a3b..75f627a 100644
--- a/chrome/browser/history/snippet_unittest.cc
+++ b/chrome/browser/history/snippet_unittest.cc
@@ -6,6 +6,7 @@
 
 #include <algorithm>
 
+#include "base/string_split.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -162,11 +163,7 @@ TEST(Snippets, UTF8) {
             UTF16ToUTF8(BuildSnippet(kSampleDocument, "relationship")));
 }
 
-// Bug: 1274923
-// TODO(jungshik): Move this bug report to crbugs.com
-// Fails consistently. From the report, "Broken by latest ICU. Need new expected
-// results."
-TEST(Snippets, FAILS_ThaiUTF8) {
+TEST(Snippets, ThaiUTF8) {
   // There are 3 instances of '\u0E43\u0E2B\u0E49'
   // (\xE0\xB9\x83\xE0\xB8\xAB\xE0\xB9\x89) in kThaiSample.
   // The 1st is more than |kSniipetContext| graphemes away from the
@@ -174,53 +171,54 @@ TEST(Snippets, FAILS_ThaiUTF8) {
   // the 2nd match added, the snippet goes over the size limit so that
   // the snippet ends right before the 3rd match.
   ASSERT_EQ(" ... "
-            " \xE0\xB8\x82\xE0\xB9\x89\xE0\xB8\xAD\xE0\xB8\xA1\xE0\xB8\xB9"
-            "\xE0\xB8\xA5\xE0\xB8\xAA\xE0\xB9\x88\xE0\xB8\xA7\xE0\xB8\x99"
-            "\xE0\xB8\x9A\xE0\xB8\xB8\xE0\xB8\x84\xE0\xB8\x84\xE0\xB8\xA5 "
-            "\xE0\xB9\x80\xE0\xB8\xA1\xE0\xB8\xB7\xE0\xB9\x88\xE0\xB8\xAD"
-            "\xE0\xB8\x84\xE0\xB8\xB8\xE0\xB8\x93\xE0\xB8\xA5\xE0\xB8\x87"
-            "\xE0\xB8\x97\xE0\xB8\xB0\xE0\xB9\x80\xE0\xB8\x9A\xE0\xB8\xB5"
-            "\xE0\xB8\xA2\xE0\xB8\x99\xE0\xB9\x80\xE0\xB8\x9E\xE0\xB8\xB7"
-            "\xE0\xB9\x88\xE0\xB8\xAD\xE0\xB9\x83\xE0\xB8\x8A\xE0\xB9\x89"
-            "\xE0\xB8\x9A\xE0\xB8\xA3\xE0\xB8\xB4\xE0\xB8\x81\xE0\xB8\xB2"
-            "\xE0\xB8\xA3\xE0\xB8\x82\xE0\xB8\xAD\xE0\xB8\x87 Google "
-            "\xE0\xB8\xAB\xE0\xB8\xA3\xE0\xB8\xB7\xE0\xB8\xAD**\xE0\xB9\x83"
-            "\xE0\xB8\xAB\xE0\xB9\x89**\xE0\xB8\x82\xE0\xB9\x89\xE0\xB8\xAD"
-            "\xE0\xB8\xA1\xE0\xB8\xB9\xE0\xB8\xA5\xE0\xB8\x94\xE0\xB8\xB1"
-            "\xE0\xB8\x87\xE0\xB8\x81\xE0\xB8\xA5\xE0\xB9\x88\xE0\xB8\xB2"
-            "\xE0\xB8\xA7\xE0\xB9\x82\xE0\xB8\x94\xE0\xB8\xA2\xE0\xB8\xAA"
-            "\xE0\xB8\xA1\xE0\xB8\xB1\xE0\xB8\x84\xE0\xB8\xA3\xE0\xB9\x83"
-            "\xE0\xB8\x88 \xE0\xB9\x80\xE0\xB8\xA3\xE0\xB8\xB2\xE0\xB8\xAD"
-            "\xE0\xB8\xB2\xE0\xB8\x88\xE0\xB8\xA3\xE0\xB8\xA7\xE0\xB8\xA1"
-            "\xE0\xB8\x82\xE0\xB9\x89\xE0\xB8\xAD\xE0\xB8\xA1\xE0\xB8\xB9"
-            "\xE0\xB8\xA5\xE0\xB8\xAA\xE0\xB9\x88\xE0\xB8\xA7\xE0\xB8\x99"
-            "\xE0\xB8\x9A\xE0\xB8\xB8\xE0\xB8\x84\xE0\xB8\x84\xE0\xB8\xA5"
-            "\xE0\xB8\x97\xE0\xB8\xB5\xE0\xB9\x88\xE0\xB9\x80\xE0\xB8\x81"
-            "\xE0\xB9\x87\xE0\xB8\x9A\xE0\xB8\xA3\xE0\xB8\xA7\xE0\xB8\x9A"
-            "\xE0\xB8\xA3\xE0\xB8\xA7\xE0\xB8\xA1 ...  ... "
+            "\xE0\xB8\xA3\xE0\xB8\xA7\xE0\xB8\x9A\xE0\xB8\xA3\xE0\xB8\xA7"
+            "\xE0\xB8\xA1 \xE0\xB8\x82\xE0\xB9\x89\xE0\xB8\xAD\xE0\xB8"
+            "\xA1\xE0\xB8\xB9\xE0\xB8\xA5\xE0\xB8\xAA\xE0\xB9\x88\xE0\xB8"
+            "\xA7\xE0\xB8\x99\xE0\xB8\x9A\xE0\xB8\xB8\xE0\xB8\x84\xE0\xB8"
+            "\x84\xE0\xB8\xA5 \xE0\xB9\x80\xE0\xB8\xA1\xE0\xB8\xB7\xE0"
+            "\xB9\x88\xE0\xB8\xAD\xE0\xB8\x84\xE0\xB8\xB8\xE0\xB8\x93\xE0"
+            "\xB8\xA5\xE0\xB8\x87\xE0\xB8\x97\xE0\xB8\xB0\xE0\xB9\x80\xE0"
+            "\xB8\x9A\xE0\xB8\xB5\xE0\xB8\xA2\xE0\xB8\x99\xE0\xB9\x80\xE0"
+            "\xB8\x9E\xE0\xB8\xB7\xE0\xB9\x88\xE0\xB8\xAD\xE0\xB9\x83\xE0"
+            "\xB8\x8A\xE0\xB9\x89\xE0\xB8\x9A\xE0\xB8\xA3\xE0\xB8\xB4\xE0"
+            "\xB8\x81\xE0\xB8\xB2\xE0\xB8\xA3\xE0\xB8\x82\xE0\xB8\xAD\xE0"
+            "\xB8\x87 Google \xE0\xB8\xAB\xE0\xB8\xA3\xE0\xB8\xB7\xE0\xB8"
+            "\xAD**\xE0\xB9\x83\xE0\xB8\xAB\xE0\xB9\x89**\xE0\xB8\x82\xE0"
+            "\xB9\x89\xE0\xB8\xAD\xE0\xB8\xA1\xE0\xB8\xB9\xE0\xB8\xA5\xE0"
+            "\xB8\x94\xE0\xB8\xB1\xE0\xB8\x87\xE0\xB8\x81\xE0\xB8\xA5\xE0"
+            "\xB9\x88\xE0\xB8\xB2\xE0\xB8\xA7\xE0\xB9\x82\xE0\xB8\x94\xE0"
+            "\xB8\xA2\xE0\xB8\xAA\xE0\xB8\xA1\xE0\xB8\xB1\xE0\xB8\x84\xE0"
+            "\xB8\xA3\xE0\xB9\x83\xE0\xB8\x88 \xE0\xB9\x80\xE0\xB8\xA3"
+            "\xE0\xB8\xB2\xE0\xB8\xAD\xE0\xB8\xB2\xE0\xB8\x88\xE0\xB8\xA3"
+            "\xE0\xB8\xA7\xE0\xB8\xA1\xE0\xB8\x82\xE0\xB9\x89\xE0\xB8\xAD"
+            "\xE0\xB8\xA1\xE0\xB8\xB9\xE0\xB8\xA5\xE0\xB8\xAA\xE0\xB9\x88"
+            "\xE0\xB8\xA7\xE0\xB8\x99\xE0\xB8\x9A\xE0\xB8\xB8\xE0\xB8\x84"
+            "\xE0\xB8\x84\xE0\xB8\xA5\xE0\xB8\x97\xE0\xB8\xB5\xE0\xB9\x88"
+            "\xE0\xB9\x80\xE0\xB8\x81\xE0\xB9\x87\xE0\xB8\x9A\xE0\xB8\xA3"
+            "\xE0\xB8\xA7\xE0\xB8\x9A\xE0\xB8\xA3\xE0\xB8\xA7\xE0\xB8\xA1"
             "\xE0\xB8\x88\xE0\xB8\xB2\xE0\xB8\x81\xE0\xB8\x84\xE0\xB8\xB8"
             "\xE0\xB8\x93\xE0\xB9\x80\xE0\xB8\x82\xE0\xB9\x89\xE0\xB8\xB2"
-            "\xE0\xB8\x81\xE0\xB8\xB1\xE0\xB8\x9A\xE0\xB8\x82\xE0\xB9\x89"
-            "\xE0\xB8\xAD\xE0\xB8\xA1\xE0\xB8\xB9\xE0\xB8\xA5\xE0\xB8\x88"
-            "\xE0\xB8\xB2\xE0\xB8\x81\xE0\xB8\x9A\xE0\xB8\xA3\xE0\xB8\xB4"
-            "\xE0\xB8\x81\xE0\xB8\xB2\xE0\xB8\xA3\xE0\xB8\xAD\xE0\xB8\xB7"
-            "\xE0\xB9\x88\xE0\xB8\x99\xE0\xB8\x82\xE0\xB8\xAD\xE0\xB8\x87 "
-            "Google \xE0\xB8\xAB\xE0\xB8\xA3\xE0\xB8\xB7\xE0\xB8\xAD"
-            "\xE0\xB8\x9A\xE0\xB8\xB8\xE0\xB8\x84\xE0\xB8\x84\xE0\xB8\xA5"
-            "\xE0\xB8\x97\xE0\xB8\xB5\xE0\xB9\x88\xE0\xB8\xAA\xE0\xB8\xB2"
-            "\xE0\xB8\xA1 \xE0\xB9\x80\xE0\xB8\x9E\xE0\xB8\xB7\xE0\xB9\x88"
-            "\xE0\xB8\xAD**\xE0\xB9\x83\xE0\xB8\xAB\xE0\xB9\x89**\xE0\xB8\x9C"
-            "\xE0\xB8\xB9\xE0\xB9\x89\xE0\xB9\x83\xE0\xB8\x8A\xE0\xB9\x89"
-            "\xE0\xB9\x84\xE0\xB8\x94\xE0\xB9\x89\xE0\xB8\xA3\xE0\xB8\xB1"
-            "\xE0\xB8\x9A\xE0\xB8\x9B\xE0\xB8\xA3\xE0\xB8\xB0\xE0\xB8\xAA"
-            "\xE0\xB8\x9A\xE0\xB8\x81\xE0\xB8\xB2\xE0\xB8\xA3\xE0\xB8\x93"
-            "\xE0\xB9\x8C\xE0\xB8\x97\xE0\xB8\xB5\xE0\xB9\x88\xE0\xB8\x94"
-            "\xE0\xB8\xB5\xE0\xB8\x82\xE0\xB8\xB6\xE0\xB9\x89\xE0\xB8\x99 "
-            "\xE0\xB8\xA3\xE0\xB8\xA7\xE0\xB8\xA1\xE0\xB8\x97\xE0\xB8\xB1"
-            "\xE0\xB9\x89\xE0\xB8\x87\xE0\xB8\x9B\xE0\xB8\xA3\xE0\xB8\xB1"
-            "\xE0\xB8\x9A\xE0\xB9\x81\xE0\xB8\x95\xE0\xB9\x88\xE0\xB8\x87"
-            "\xE0\xB9\x80\xE0\xB8\x99\xE0\xB8\xB7\xE0\xB9\x89\xE0\xB8\xAD"
-            "\xE0\xB8\xAB\xE0\xB8\xB2",
+            "\xE0\xB8\x81\xE0\xB8\xB1\xE0\xB8\x9A ...  ... \xE0\xB8\x82"
+            "\xE0\xB9\x89\xE0\xB8\xAD\xE0\xB8\xA1\xE0\xB8\xB9\xE0\xB8\xA5"
+            "\xE0\xB8\x88\xE0\xB8\xB2\xE0\xB8\x81\xE0\xB8\x9A\xE0\xB8\xA3"
+            "\xE0\xB8\xB4\xE0\xB8\x81\xE0\xB8\xB2\xE0\xB8\xA3\xE0\xB8\xAD"
+            "\xE0\xB8\xB7\xE0\xB9\x88\xE0\xB8\x99\xE0\xB8\x82\xE0\xB8\xAD"
+            "\xE0\xB8\x87 Google \xE0\xB8\xAB\xE0\xB8\xA3\xE0\xB8\xB7\xE0"
+            "\xB8\xAD\xE0\xB8\x9A\xE0\xB8\xB8\xE0\xB8\x84\xE0\xB8\x84\xE0"
+            "\xB8\xA5\xE0\xB8\x97\xE0\xB8\xB5\xE0\xB9\x88\xE0\xB8\xAA\xE0"
+            "\xB8\xB2\xE0\xB8\xA1 \xE0\xB9\x80\xE0\xB8\x9E\xE0\xB8\xB7"
+            "\xE0\xB9\x88\xE0\xB8\xAD**\xE0\xB9\x83\xE0\xB8\xAB\xE0\xB9"
+            "\x89**\xE0\xB8\x9C\xE0\xB8\xB9\xE0\xB9\x89\xE0\xB9\x83\xE0"
+            "\xB8\x8A\xE0\xB9\x89\xE0\xB9\x84\xE0\xB8\x94\xE0\xB9\x89\xE0"
+            "\xB8\xA3\xE0\xB8\xB1\xE0\xB8\x9A\xE0\xB8\x9B\xE0\xB8\xA3\xE0"
+            "\xB8\xB0\xE0\xB8\xAA\xE0\xB8\x9A\xE0\xB8\x81\xE0\xB8\xB2\xE0"
+            "\xB8\xA3\xE0\xB8\x93\xE0\xB9\x8C\xE0\xB8\x97\xE0\xB8\xB5\xE0"
+            "\xB9\x88\xE0\xB8\x94\xE0\xB8\xB5\xE0\xB8\x82\xE0\xB8\xB6\xE0"
+            "\xB9\x89\xE0\xB8\x99 \xE0\xB8\xA3\xE0\xB8\xA7\xE0\xB8\xA1"
+            "\xE0\xB8\x97\xE0\xB8\xB1\xE0\xB9\x89\xE0\xB8\x87\xE0\xB8\x9B"
+            "\xE0\xB8\xA3\xE0\xB8\xB1\xE0\xB8\x9A\xE0\xB9\x81\xE0\xB8\x95"
+            "\xE0\xB9\x88\xE0\xB8\x87\xE0\xB9\x80\xE0\xB8\x99\xE0\xB8\xB7"
+            "\xE0\xB9\x89\xE0\xB8\xAD\xE0\xB8\xAB\xE0\xB8\xB2",
             UTF16ToUTF8(BuildSnippet(kThaiSample,
                                      "\xE0\xB9\x83\xE0\xB8\xAB\xE0\xB9\x89")));
 }
diff --git a/chrome/browser/history/starred_url_database.cc b/chrome/browser/history/starred_url_database.cc
index cf2a306..ba8b27d 100644
--- a/chrome/browser/history/starred_url_database.cc
+++ b/chrome/browser/history/starred_url_database.cc
@@ -4,7 +4,6 @@
 
 #include "chrome/browser/history/starred_url_database.h"
 
-#include "app/sql/connection.h"
 #include "app/sql/statement.h"
 #include "base/file_util.h"
 #include "base/logging.h"
@@ -12,6 +11,7 @@
 #include "base/scoped_vector.h"
 #include "base/stl_util-inl.h"
 #include "base/string_util.h"
+#include "base/utf_string_conversions.h"
 #include "base/values.h"
 #include "chrome/browser/bookmarks/bookmark_codec.h"
 #include "chrome/browser/bookmarks/bookmark_model.h"
diff --git a/chrome/browser/history/starred_url_database.h b/chrome/browser/history/starred_url_database.h
index 8d327d8..aab2ae5 100644
--- a/chrome/browser/history/starred_url_database.h
+++ b/chrome/browser/history/starred_url_database.h
@@ -4,6 +4,7 @@
 
 #ifndef CHROME_BROWSER_HISTORY_STARRED_URL_DATABASE_H_
 #define CHROME_BROWSER_HISTORY_STARRED_URL_DATABASE_H_
+#pragma once
 
 #include <set>
 
diff --git a/chrome/browser/history/starred_url_database_unittest.cc b/chrome/browser/history/starred_url_database_unittest.cc
index f82e645..deb9750 100644
--- a/chrome/browser/history/starred_url_database_unittest.cc
+++ b/chrome/browser/history/starred_url_database_unittest.cc
@@ -7,6 +7,7 @@
 #include "base/file_util.h"
 #include "base/path_service.h"
 #include "base/string_util.h"
+#include "base/utf_string_conversions.h"
 #include "chrome/browser/history/history.h"
 #include "chrome/browser/history/starred_url_database.h"
 #include "chrome/common/chrome_paths.h"
diff --git a/chrome/browser/history/text_database.cc b/chrome/browser/history/text_database.cc
index 3327869..71c801f 100644
--- a/chrome/browser/history/text_database.cc
+++ b/chrome/browser/history/text_database.cc
@@ -8,12 +8,12 @@
 
 #include "chrome/browser/history/text_database.h"
 
-#include "app/sql/connection.h"
 #include "app/sql/statement.h"
 #include "app/sql/transaction.h"
 #include "base/file_util.h"
 #include "base/histogram.h"
 #include "base/logging.h"
+#include "base/string_number_conversions.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/diagnostics/sqlite_diagnostics.h"
@@ -107,8 +107,9 @@ TextDatabase::DBIdent TextDatabase::FileNameToID(const FilePath& file_path) {
     return 0;
   }
 
-  int year = StringToInt(suffix.substr(0, 4));
-  int month = StringToInt(suffix.substr(5, 2));
+  int year, month;
+  base::StringToInt(suffix.substr(0, 4), &year);
+  base::StringToInt(suffix.substr(5, 2), &month);
 
   return year * 100 + month;
 }
@@ -127,7 +128,7 @@ bool TextDatabase::Init() {
   // better performance (we're typically seek rather than bandwidth limited).
   // This only has an effect before any tables have been created, otherwise
   // this is a NOP. Must be a power of 2 and a max of 8192.
-  db_.set_page_size(2096);
+  db_.set_page_size(4096);
 
   // The default cache size is 2000 which give >8MB of data. Since we will often
   // have 2-3 of these objects, each with their own 8MB, this adds up very fast.
diff --git a/chrome/browser/history/text_database.h b/chrome/browser/history/text_database.h
index e34c071..e881888 100644
--- a/chrome/browser/history/text_database.h
+++ b/chrome/browser/history/text_database.h
@@ -4,6 +4,7 @@
 
 #ifndef CHROME_BROWSER_HISTORY_TEXT_DATABASE_H_
 #define CHROME_BROWSER_HISTORY_TEXT_DATABASE_H_
+#pragma once
 
 #include <set>
 #include <vector>
diff --git a/chrome/browser/history/text_database_manager.h b/chrome/browser/history/text_database_manager.h
index 7f25bf7..5f8d1a3 100644
--- a/chrome/browser/history/text_database_manager.h
+++ b/chrome/browser/history/text_database_manager.h
@@ -4,6 +4,7 @@
 
 #ifndef CHROME_BROWSER_HISTORY_TEXT_DATABASE_MANAGER_H_
 #define CHROME_BROWSER_HISTORY_TEXT_DATABASE_MANAGER_H_
+#pragma once
 
 #include <set>
 #include <vector>
@@ -275,7 +276,7 @@ class TextDatabaseManager {
   typedef OwningMRUCache<TextDatabase::DBIdent, TextDatabase*> DBCache;
   DBCache db_cache_;
 
-  // Tells us about the existance of database files on disk. All existing
+  // Tells us about the existence of database files on disk. All existing
   // databases will be in here, and non-existant ones will not, so we don't
   // have to check the disk every time.
   //
diff --git a/chrome/browser/history/text_database_manager_unittest.cc b/chrome/browser/history/text_database_manager_unittest.cc
index 8e7f27e..1ec7744 100644
--- a/chrome/browser/history/text_database_manager_unittest.cc
+++ b/chrome/browser/history/text_database_manager_unittest.cc
@@ -79,7 +79,7 @@ void AddAllPages(TextDatabaseManager& manager, VisitDatabase* visit_db,
   visit_row.transition = 0;
   visit_row.segment_id = 0;
   visit_row.is_indexed = false;
-  VisitID visit_id = visit_db->AddVisit(&visit_row);
+  VisitID visit_id = visit_db->AddVisit(&visit_row, SOURCE_BROWSED);
 
   times->push_back(visit_row.visit_time);
   manager.AddPageData(GURL(kURL1), visit_row.url_id, visit_row.visit_id,
@@ -89,7 +89,7 @@ void AddAllPages(TextDatabaseManager& manager, VisitDatabase* visit_db,
   exploded.day_of_month++;
   visit_row.url_id = 2;
   visit_row.visit_time = Time::FromUTCExploded(exploded);
-  visit_id = visit_db->AddVisit(&visit_row);
+  visit_id = visit_db->AddVisit(&visit_row, SOURCE_BROWSED);
   times->push_back(visit_row.visit_time);
   manager.AddPageData(GURL(kURL2), visit_row.url_id, visit_row.visit_id,
                       visit_row.visit_time, UTF8ToUTF16(kTitle2),
@@ -98,7 +98,7 @@ void AddAllPages(TextDatabaseManager& manager, VisitDatabase* visit_db,
   exploded.day_of_month++;
   visit_row.url_id = 2;
   visit_row.visit_time = Time::FromUTCExploded(exploded);
-  visit_id = visit_db->AddVisit(&visit_row);
+  visit_id = visit_db->AddVisit(&visit_row, SOURCE_BROWSED);
   times->push_back(visit_row.visit_time);
   manager.AddPageData(GURL(kURL3), visit_row.url_id, visit_row.visit_id,
                       visit_row.visit_time, UTF8ToUTF16(kTitle3),
@@ -108,7 +108,7 @@ void AddAllPages(TextDatabaseManager& manager, VisitDatabase* visit_db,
   exploded.month++;
   visit_row.url_id = 2;
   visit_row.visit_time = Time::FromUTCExploded(exploded);
-  visit_id = visit_db->AddVisit(&visit_row);
+  visit_id = visit_db->AddVisit(&visit_row, SOURCE_BROWSED);
   times->push_back(visit_row.visit_time);
   manager.AddPageData(GURL(kURL4), visit_row.url_id, visit_row.visit_id,
                       visit_row.visit_time, UTF8ToUTF16(kTitle4),
@@ -117,7 +117,7 @@ void AddAllPages(TextDatabaseManager& manager, VisitDatabase* visit_db,
   exploded.day_of_month++;
   visit_row.url_id = 2;
   visit_row.visit_time = Time::FromUTCExploded(exploded);
-  visit_id = visit_db->AddVisit(&visit_row);
+  visit_id = visit_db->AddVisit(&visit_row, SOURCE_BROWSED);
   times->push_back(visit_row.visit_time);
   manager.AddPageData(GURL(kURL5), visit_row.url_id, visit_row.visit_id,
                       visit_row.visit_time, UTF8ToUTF16(kTitle5),
@@ -127,7 +127,7 @@ void AddAllPages(TextDatabaseManager& manager, VisitDatabase* visit_db,
   exploded.day_of_month++;
   visit_row.url_id = 2;
   visit_row.visit_time = Time::FromUTCExploded(exploded);
-  visit_id = visit_db->AddVisit(&visit_row);
+  visit_id = visit_db->AddVisit(&visit_row, SOURCE_BROWSED);
   times->push_back(visit_row.visit_time);
   manager.AddPageData(GURL(kURL1), visit_row.url_id, visit_row.visit_id,
                       visit_row.visit_time, UTF8ToUTF16(kTitle1),
@@ -242,7 +242,7 @@ TEST_F(TextDatabaseManagerTest, InsertCompleteVisit) {
   visit.transition = PageTransition::LINK;
   visit.segment_id = 0;
   visit.is_indexed = false;
-  visit_db.AddVisit(&visit);
+  visit_db.AddVisit(&visit, SOURCE_BROWSED);
 
   // Add a full text indexed entry for that visit.
   const GURL url(kURL2);
@@ -335,7 +335,7 @@ TEST_F(TextDatabaseManagerTest, PartialComplete) {
   VisitRow visit_row;
   visit_row.url_id = url_id;
   visit_row.visit_time = added_time;
-  visit_db.AddVisit(&visit_row);
+  visit_db.AddVisit(&visit_row, SOURCE_BROWSED);
 
   // Add a URL with no title or body, and say that it expired.
   manager.AddPageURL(url, 0, 0, added_time);
diff --git a/chrome/browser/history/thumbnail_database.cc b/chrome/browser/history/thumbnail_database.cc
index 8bf203d..36b8a20 100644
--- a/chrome/browser/history/thumbnail_database.cc
+++ b/chrome/browser/history/thumbnail_database.cc
@@ -8,21 +8,23 @@
 #include "app/sql/transaction.h"
 #include "base/command_line.h"
 #include "base/file_util.h"
-#if defined(OS_MACOSX)
-#include "base/mac_util.h"
-#endif
 #include "base/ref_counted_memory.h"
 #include "base/time.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/diagnostics/sqlite_diagnostics.h"
 #include "chrome/browser/history/history_publisher.h"
+#include "chrome/browser/history/top_sites.h"
 #include "chrome/browser/history/url_database.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/thumbnail_score.h"
 #include "gfx/codec/jpeg_codec.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 
+#if defined(OS_MACOSX)
+#include "base/mac_util.h"
+#endif
+
 namespace history {
 
 // Version number of the database.
@@ -130,7 +132,7 @@ sql::InitStatus ThumbnailDatabase::OpenDatabase(sql::Connection* db,
 
 bool ThumbnailDatabase::InitThumbnailTable() {
   if (!db_.DoesTableExist("thumbnails")) {
-    if (CommandLine::ForCurrentProcess()-> HasSwitch(switches::kTopSites)) {
+    if (history::TopSites::IsEnabled()) {
       use_top_sites_ = true;
       return true;
     }
@@ -231,8 +233,10 @@ void ThumbnailDatabase::SetPageThumbnail(
     const SkBitmap& thumbnail,
     const ThumbnailScore& score,
     base::Time time) {
-  if (use_top_sites_)
+  if (use_top_sites_) {
+    LOG(WARNING) << "Use TopSites instead.";
     return;  // Not possible after migration to TopSites.
+  }
 
   if (!thumbnail.isNull()) {
     bool add_thumbnail = true;
@@ -286,8 +290,10 @@ void ThumbnailDatabase::SetPageThumbnail(
 
 bool ThumbnailDatabase::GetPageThumbnail(URLID id,
                                          std::vector<unsigned char>* data) {
-  if (use_top_sites_)
+  if (use_top_sites_) {
+    LOG(WARNING) << "Use TopSites instead.";
     return false;  // Not possible after migration to TopSites.
+  }
 
   sql::Statement statement(db_.GetCachedStatement(SQL_FROM_HERE,
       "SELECT data FROM thumbnails WHERE url_id=?"));
@@ -303,8 +309,10 @@ bool ThumbnailDatabase::GetPageThumbnail(URLID id,
 }
 
 bool ThumbnailDatabase::DeleteThumbnail(URLID id) {
-  if (use_top_sites_)
+  if (use_top_sites_) {
+    LOG(WARNING) << "Use TopSites instead.";
     return true;  // Not possible after migration to TopSites.
+  }
 
   sql::Statement statement(db_.GetCachedStatement(SQL_FROM_HERE,
       "DELETE FROM thumbnails WHERE url_id = ?"));
@@ -317,8 +325,10 @@ bool ThumbnailDatabase::DeleteThumbnail(URLID id) {
 
 bool ThumbnailDatabase::ThumbnailScoreForId(URLID id,
                                             ThumbnailScore* score) {
-  if (use_top_sites_)
+  if (use_top_sites_) {
+    LOG(WARNING) << "Use TopSites instead.";
     return false;  // Not possible after migration to TopSites.
+  }
 
   // Fetch the current thumbnail's information to make sure we
   // aren't replacing a good thumbnail with one that's worse.
@@ -491,7 +501,8 @@ bool ThumbnailDatabase::RenameAndDropThumbnails(const FilePath& old_db_file,
   favicons.Close();
 
   // Can't attach within a transaction.
-  CommitTransaction();
+  if (transaction_nesting())
+    CommitTransaction();
 
   // Attach new DB.
   {
diff --git a/chrome/browser/history/thumbnail_database.h b/chrome/browser/history/thumbnail_database.h
index 81d498c..94fb043 100644
--- a/chrome/browser/history/thumbnail_database.h
+++ b/chrome/browser/history/thumbnail_database.h
@@ -4,6 +4,7 @@
 
 #ifndef CHROME_BROWSER_HISTORY_THUMBNAIL_DATABASE_H_
 #define CHROME_BROWSER_HISTORY_THUMBNAIL_DATABASE_H_
+#pragma once
 
 #include <vector>
 
diff --git a/chrome/browser/history/thumbnail_database_unittest.cc b/chrome/browser/history/thumbnail_database_unittest.cc
index 4d2c2bf..23eccef 100644
--- a/chrome/browser/history/thumbnail_database_unittest.cc
+++ b/chrome/browser/history/thumbnail_database_unittest.cc
@@ -6,6 +6,7 @@
 #include <vector>
 
 #include "base/basictypes.h"
+#include "base/command_line.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
 #include "base/path_service.h"
@@ -13,6 +14,8 @@
 #include "base/scoped_temp_dir.h"
 #include "chrome/browser/history/thumbnail_database.h"
 #include "chrome/common/chrome_paths.h"
+#include "chrome/common/chrome_switches.h"
+#include "chrome/browser/history/top_sites.h"
 #include "chrome/common/thumbnail_score.h"
 #include "chrome/tools/profiles/thumbnail-inl.h"
 #include "gfx/codec/jpeg_codec.h"
@@ -70,6 +73,9 @@ class ThumbnailDatabaseTest : public testing::Test {
 };
 
 TEST_F(ThumbnailDatabaseTest, AddDelete) {
+  if (history::TopSites::IsEnabled())
+    return;  // TopSitesTest replaces this.
+
   ThumbnailDatabase db;
   ASSERT_EQ(sql::INIT_OK, db.Init(file_name_, NULL));
 
@@ -112,6 +118,9 @@ TEST_F(ThumbnailDatabaseTest, AddDelete) {
 }
 
 TEST_F(ThumbnailDatabaseTest, UseLessBoringThumbnails) {
+  if (history::TopSites::IsEnabled())
+    return;  // TopSitesTest replaces this.
+
   ThumbnailDatabase db;
   Time now = Time::Now();
   ASSERT_EQ(sql::INIT_OK, db.Init(file_name_, NULL));
@@ -146,6 +155,9 @@ TEST_F(ThumbnailDatabaseTest, UseLessBoringThumbnails) {
 }
 
 TEST_F(ThumbnailDatabaseTest, UseAtTopThumbnails) {
+  if (history::TopSites::IsEnabled())
+    return;  // TopSitesTest replaces this.
+
   ThumbnailDatabase db;
   Time now = Time::Now();
   ASSERT_EQ(sql::INIT_OK, db.Init(file_name_, NULL));
@@ -217,6 +229,9 @@ TEST_F(ThumbnailDatabaseTest, UseAtTopThumbnails) {
 }
 
 TEST_F(ThumbnailDatabaseTest, ThumbnailTimeDegradation) {
+  if (history::TopSites::IsEnabled())
+    return;  // TopSitesTest replaces this.
+
   ThumbnailDatabase db;
   const Time kNow = Time::Now();
   const Time kThreeHoursAgo = kNow - TimeDelta::FromHours(4);
@@ -261,6 +276,9 @@ TEST_F(ThumbnailDatabaseTest, NeverAcceptTotallyBoringThumbnail) {
   // should replace a thumbnail with another because of reasons other
   // than straight up boringness score, still reject because the
   // thumbnail is totally boring.
+  if (history::TopSites::IsEnabled())
+    return;  // TopSitesTest replaces this.
+
   ThumbnailDatabase db;
   Time now = Time::Now();
   ASSERT_EQ(sql::INIT_OK, db.Init(file_name_, NULL));
@@ -332,6 +350,9 @@ TEST_F(ThumbnailDatabaseTest, NeverAcceptTotallyBoringThumbnail) {
 }
 
 TEST_F(ThumbnailDatabaseTest, NeedsMigrationToTopSites) {
+  if (history::TopSites::IsEnabled())
+    return;  // TopSitesTest replaces this.
+
   ThumbnailDatabase db;
   ASSERT_EQ(sql::INIT_OK, db.Init(file_name_, NULL));
   db.BeginTransaction();
diff --git a/chrome/browser/history/top_sites.cc b/chrome/browser/history/top_sites.cc
index 1ef4dec..c9f4a94 100644
--- a/chrome/browser/history/top_sites.cc
+++ b/chrome/browser/history/top_sites.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -6,22 +6,37 @@
 
 #include <algorithm>
 
+#include "app/l10n_util.h"
+#include "base/command_line.h"
 #include "base/file_util.h"
 #include "base/logging.h"
+#include "base/md5.h"
+#include "base/string_util.h"
+#include "base/utf_string_conversions.h"
+#include "base/values.h"
 #include "chrome/browser/chrome_thread.h"
-#include "chrome/browser/profile.h"
-#include "chrome/browser/history/top_sites_database.h"
+#include "chrome/browser/dom_ui/most_visited_handler.h"
 #include "chrome/browser/history/history_notifications.h"
 #include "chrome/browser/history/page_usage_data.h"
+#include "chrome/browser/history/top_sites_database.h"
+#include "chrome/browser/prefs/pref_service.h"
+#include "chrome/browser/profile.h"
 #include "chrome/browser/tab_contents/navigation_controller.h"
 #include "chrome/browser/tab_contents/navigation_entry.h"
+#include "chrome/common/chrome_switches.h"
+#include "chrome/common/pref_names.h"
+#include "chrome/common/thumbnail_score.h"
 #include "gfx/codec/jpeg_codec.h"
+#include "grit/chromium_strings.h"
+#include "grit/generated_resources.h"
+#include "grit/locale_settings.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 
 namespace history {
 
 // How many top sites to store in the cache.
 static const size_t kTopSitesNumber = 20;
+static const size_t kTopSitesShown = 8;
 static const int kDaysOfHistory = 90;
 // Time from startup to first HistoryService query.
 static const int64 kUpdateIntervalSecs = 15;
@@ -34,11 +49,28 @@ TopSites::TopSites(Profile* profile) : profile_(profile),
                                        mock_history_service_(NULL),
                                        last_num_urls_changed_(0),
                                        migration_in_progress_(false),
-                                       waiting_for_results_(true) {
-  registrar_.Add(this, NotificationType::HISTORY_URLS_DELETED,
-                 Source<Profile>(profile_));
-  registrar_.Add(this, NotificationType::NAV_ENTRY_COMMITTED,
-                 NotificationService::AllSources());
+                                       waiting_for_results_(true),
+                                       blacklist_(NULL),
+                                       pinned_urls_(NULL) {
+  if (!profile_)
+    return;
+
+  if (NotificationService::current()) {
+    registrar_.Add(this, NotificationType::HISTORY_URLS_DELETED,
+                   Source<Profile>(profile_));
+    registrar_.Add(this, NotificationType::NAV_ENTRY_COMMITTED,
+                   NotificationService::AllSources());
+  }
+
+  blacklist_ = profile_->GetPrefs()->
+      GetMutableDictionary(prefs::kNTPMostVisitedURLsBlacklist);
+  pinned_urls_ = profile_->GetPrefs()->
+      GetMutableDictionary(prefs::kNTPMostVisitedPinnedURLs);
+}
+
+// static
+bool TopSites::IsEnabled() {
+  return CommandLine::ForCurrentProcess()->HasSwitch(switches::kEnableTopSites);
 }
 
 TopSites::~TopSites() {
@@ -66,19 +98,18 @@ void TopSites::ReadDatabase() {
   std::map<GURL, Images> thumbnails;
 
   DCHECK(db_.get());
-  {
-    AutoLock lock(lock_);
-    MostVisitedURLList top_urls;
-    db_->GetPageThumbnails(&top_urls, &thumbnails);
-    StoreMostVisited(&top_urls);
-  }  // Lock is released here.
+  MostVisitedURLList top_urls;
+  db_->GetPageThumbnails(&top_urls, &thumbnails);
+  MostVisitedURLList copy(top_urls);  // StoreMostVisited destroys the list.
+  StoreMostVisited(&top_urls);
+  if (AddPrepopulatedPages(&copy))
+    UpdateMostVisited(copy);
 
+  AutoLock lock(lock_);
   for (size_t i = 0; i < top_sites_.size(); i++) {
     GURL url = top_sites_[i].url;
     Images thumbnail = thumbnails[url];
-    if (!thumbnail.thumbnail.get() || !thumbnail.thumbnail->size()) {
-      LOG(INFO) << "No thumbnail for " << url.spec();
-    } else {
+    if (thumbnail.thumbnail.get() && thumbnail.thumbnail->size()) {
       SetPageThumbnailNoDB(url, thumbnail.thumbnail,
                            thumbnail.thumbnail_score);
     }
@@ -90,6 +121,7 @@ void TopSites::ReadDatabase() {
 bool TopSites::SetPageThumbnail(const GURL& url,
                                 const SkBitmap& thumbnail,
                                 const ThumbnailScore& score) {
+  AutoLock lock(lock_);
   bool add_temp_thumbnail = false;
   if (canonical_urls_.find(url) == canonical_urls_.end()) {
     if (top_sites_.size() < kTopSitesNumber) {
@@ -118,12 +150,13 @@ bool TopSites::SetPageThumbnail(const GURL& url,
     return true;
   }
 
-  return SetPageThumbnail(url, thumbnail_data, score);
+  return SetPageThumbnailEncoded(url, thumbnail_data, score);
 }
 
-bool TopSites::SetPageThumbnail(const GURL& url,
-                                const RefCountedBytes* thumbnail,
-                                const ThumbnailScore& score) {
+bool TopSites::SetPageThumbnailEncoded(const GURL& url,
+                                       const RefCountedBytes* thumbnail,
+                                       const ThumbnailScore& score) {
+  lock_.AssertAcquired();
   if (!SetPageThumbnailNoDB(url, thumbnail, score))
     return false;
 
@@ -144,7 +177,7 @@ bool TopSites::SetPageThumbnail(const GURL& url,
 
 void TopSites::WriteThumbnailToDB(const MostVisitedURL& url,
                                   int url_rank,
-                                  const TopSites::Images& thumbnail) {
+                                  const Images& thumbnail) {
   DCHECK(db_.get());
   DCHECK(ChromeThread::CurrentlyOn(ChromeThread::DB));
   db_->SetPageThumbnail(url, url_rank, thumbnail);
@@ -154,7 +187,7 @@ void TopSites::WriteThumbnailToDB(const MostVisitedURL& url,
 bool TopSites::SetPageThumbnailNoDB(const GURL& url,
                                     const RefCountedBytes* thumbnail_data,
                                     const ThumbnailScore& score) {
-  AutoLock lock(lock_);
+  lock_.AssertAcquired();
 
   std::map<GURL, size_t>::iterator found = canonical_urls_.find(url);
   if (found == canonical_urls_.end()) {
@@ -195,45 +228,180 @@ bool TopSites::SetPageThumbnailNoDB(const GURL& url,
 
 void TopSites::GetMostVisitedURLs(CancelableRequestConsumer* consumer,
                                   GetTopSitesCallback* callback) {
-
   scoped_refptr<CancelableRequest<GetTopSitesCallback> > request(
       new CancelableRequest<GetTopSitesCallback>(callback));
   // This ensures cancelation of requests when either the consumer or the
   // provider is deleted. Deletion of requests is also guaranteed.
   AddRequest(request, consumer);
-  if (waiting_for_results_) {
-    // A request came in before we have any top sites.
-    // We have to keep track of the requests ourselves.
-    pending_callbacks_.insert(request);
-    return;
+  MostVisitedURLList filtered_urls;
+  {
+    AutoLock lock(lock_);
+    if (waiting_for_results_) {
+      // A request came in before we have any top sites.
+      // We have to keep track of the requests ourselves.
+      pending_callbacks_.insert(request);
+      return;
+    }
+    if (request->canceled())
+      return;
+
+    ApplyBlacklistAndPinnedURLs(top_sites_, &filtered_urls);
   }
-  if (request->canceled())
-    return;
-  request->ForwardResult(GetTopSitesCallback::TupleType(top_sites_));
+  request->ForwardResult(GetTopSitesCallback::TupleType(filtered_urls));
 }
 
 bool TopSites::GetPageThumbnail(const GURL& url, RefCountedBytes** data) const {
-  std::map<GURL, Images>::const_iterator found = top_images_.find(url);
-  if (found == top_images_.end())
-    return false;  // No thumbnail for this URL.
+  AutoLock lock(lock_);
+  std::map<GURL, Images>::const_iterator found =
+      top_images_.find(GetCanonicalURL(url));
+  if (found == top_images_.end()) {
+    found = temp_thumbnails_map_.find(url);
+    if (found == temp_thumbnails_map_.end())
+      return false;  // No thumbnail for this URL.
+  }
 
   Images image = found->second;
   *data = image.thumbnail.get();
   return true;
 }
 
+static int IndexOf(const MostVisitedURLList& urls, const GURL& url) {
+  for (size_t i = 0; i < urls.size(); i++) {
+    if (urls[i].url == url)
+      return i;
+  }
+  return -1;
+}
+
+bool TopSites::AddPrepopulatedPages(MostVisitedURLList* urls) {
+  // TODO(arv): This needs to get the data from some configurable place.
+  // http://crbug.com/17630
+  bool added = false;
+  GURL welcome_url(l10n_util::GetStringUTF8(IDS_CHROME_WELCOME_URL));
+  if (urls->size() < kTopSitesNumber && IndexOf(*urls, welcome_url) == -1) {
+    MostVisitedURL url = {
+      welcome_url,
+      GURL("chrome://theme/IDR_NEWTAB_CHROME_WELCOME_PAGE_FAVICON"),
+      l10n_util::GetStringUTF16(IDS_NEW_TAB_CHROME_WELCOME_PAGE_TITLE)
+    };
+    url.redirects.push_back(welcome_url);
+    urls->push_back(url);
+    added = true;
+  }
+
+  GURL themes_url(l10n_util::GetStringUTF8(IDS_THEMES_GALLERY_URL));
+  if (urls->size() < kTopSitesNumber && IndexOf(*urls, themes_url) == -1) {
+    MostVisitedURL url = {
+      themes_url,
+      GURL("chrome://theme/IDR_NEWTAB_THEMES_GALLERY_FAVICON"),
+      l10n_util::GetStringUTF16(IDS_NEW_TAB_THEMES_GALLERY_PAGE_TITLE)
+    };
+    url.redirects.push_back(themes_url);
+    urls->push_back(url);
+    added = true;
+  }
+
+  return added;
+}
+
+void TopSites::MigratePinnedURLs() {
+  std::map<GURL, size_t> tmp_map;
+  for (DictionaryValue::key_iterator it = pinned_urls_->begin_keys();
+       it != pinned_urls_->end_keys(); ++it) {
+    Value* value;
+    if (!pinned_urls_->GetWithoutPathExpansion(*it, &value))
+      continue;
+
+    if (value->IsType(DictionaryValue::TYPE_DICTIONARY)) {
+      DictionaryValue* dict = static_cast<DictionaryValue*>(value);
+      std::string url_string;
+      int index;
+      if (dict->GetString("url", &url_string) &&
+          dict->GetInteger("index", &index))
+        tmp_map[GURL(url_string)] = index;
+    }
+  }
+  pinned_urls_->Clear();
+  for (std::map<GURL, size_t>::iterator it = tmp_map.begin();
+       it != tmp_map.end(); ++it)
+    AddPinnedURL(it->first, it->second);
+}
+
+void TopSites::ApplyBlacklistAndPinnedURLs(const MostVisitedURLList& urls,
+                                           MostVisitedURLList* out) {
+  lock_.AssertAcquired();
+  MostVisitedURLList urls_copy;
+  for (size_t i = 0; i < urls.size(); i++) {
+    if (!IsBlacklisted(urls[i].url))
+      urls_copy.push_back(urls[i]);
+  }
+
+  for (size_t pinned_index = 0; pinned_index < kTopSitesShown; pinned_index++) {
+    GURL url;
+    bool found = GetPinnedURLAtIndex(pinned_index, &url);
+    if (!found)
+      continue;
+
+    DCHECK(!url.is_empty());
+    int cur_index = IndexOf(urls_copy, url);
+    MostVisitedURL tmp;
+    if (cur_index < 0) {
+      // Pinned URL not in urls.
+      tmp.url = url;
+    } else {
+      tmp = urls_copy[cur_index];
+      urls_copy.erase(urls_copy.begin() + cur_index);
+    }
+    if (pinned_index > out->size())
+      out->resize(pinned_index);  // Add empty URLs as fillers.
+    out->insert(out->begin() + pinned_index, tmp);
+  }
+
+  // Add non-pinned URLs in the empty spots.
+  size_t current_url = 0;  // Index into the remaining URLs in urls_copy.
+  for (size_t i = 0; i < kTopSitesShown && current_url < urls_copy.size();
+       i++) {
+    if (i == out->size()) {
+      out->push_back(urls_copy[current_url]);
+      current_url++;
+    } else if (i < out->size()) {
+      if ((*out)[i].url.is_empty()) {
+        // Replace the filler
+        (*out)[i] = urls_copy[current_url];
+        current_url++;
+      }
+    } else {
+      NOTREACHED();
+    }
+  }
+}
+
+std::string TopSites::GetURLString(const GURL& url) {
+  lock_.AssertAcquired();
+  return GetCanonicalURL(url).spec();
+}
+
+std::string TopSites::GetURLHash(const GURL& url) {
+  lock_.AssertAcquired();
+  // We don't use canonical URLs here to be able to blacklist only one of
+  // the two 'duplicate' sites, e.g. 'gmail.com' and 'mail.google.com'.
+  return MD5String(url.spec());
+}
+
 void TopSites::UpdateMostVisited(MostVisitedURLList most_visited) {
   DCHECK(ChromeThread::CurrentlyOn(ChromeThread::DB));
-  // TODO(brettw) filter for blacklist!
 
-  if (!top_sites_.empty()) {
-    std::vector<size_t> added;    // Indices into most_visited.
-    std::vector<size_t> deleted;  // Indices into top_sites_.
-    std::vector<size_t> moved;    // Indices into most_visited.
-    DiffMostVisited(top_sites_, most_visited, &added, &deleted, &moved);
+  std::vector<size_t> added;    // Indices into most_visited.
+  std::vector<size_t> deleted;  // Indices into top_sites_.
+  std::vector<size_t> moved;    // Indices into most_visited.
+
+  DiffMostVisited(top_sites_, most_visited, &added, &deleted, &moved);
+
+  // #added == #deleted; #added + #moved = total.
+  last_num_urls_changed_ = added.size() + moved.size();
 
-    // #added == #deleted; #added + #moved = total.
-    last_num_urls_changed_ = added.size() + moved.size();
+  {
+    AutoLock lock(lock_);
 
     // Process the diff: delete from images and disk, add to disk.
     // Delete all the thumbnails associated with URLs that were deleted.
@@ -243,22 +411,23 @@ void TopSites::UpdateMostVisited(MostVisitedURLList most_visited) {
           top_images_.find(deleted_url.url);
       if (found != top_images_.end())
         top_images_.erase(found);
+    }
+  }
 
-      // Delete from disk.
+  // Write the updates to the DB.
+  if (db_.get()) {
+    for (size_t i = 0; i < deleted.size(); i++) {
+      const MostVisitedURL& deleted_url = top_sites_[deleted[i]];
       if (db_.get())
         db_->RemoveURL(deleted_url);
     }
-
-    if (db_.get()) {
-      // Write both added and moved urls.
-      for (size_t i = 0; i < added.size(); i++) {
-        MostVisitedURL& added_url = most_visited[added[i]];
-        db_->SetPageThumbnail(added_url, added[i], Images());
-      }
-      for (size_t i = 0; i < moved.size(); i++) {
-        MostVisitedURL moved_url = most_visited[moved[i]];
-        db_->UpdatePageRank(moved_url, moved[i]);
-      }
+    for (size_t i = 0; i < added.size(); i++) {
+      const MostVisitedURL& added_url = most_visited[added[i]];
+      db_->SetPageThumbnail(added_url, added[i], Images());
+    }
+    for (size_t i = 0; i < moved.size(); i++) {
+      const MostVisitedURL& moved_url = most_visited[moved[i]];
+      db_->UpdatePageRank(moved_url, moved[i]);
     }
   }
 
@@ -285,6 +454,9 @@ void TopSites::UpdateMostVisited(MostVisitedURLList most_visited) {
 
 void TopSites::OnMigrationDone() {
   migration_in_progress_ = false;
+  if (!profile_)
+    return;
+
   HistoryService* hs = profile_->GetHistoryService(Profile::EXPLICIT_ACCESS);
   // |hs| may be null during unit tests.
   if (!hs)
@@ -302,6 +474,12 @@ void TopSites::AddTemporaryThumbnail(const GURL& url,
 
 void TopSites::StartQueryForThumbnail(size_t index) {
   DCHECK(migration_in_progress_);
+  if (top_sites_[index].url.spec() ==
+      l10n_util::GetStringUTF8(IDS_CHROME_WELCOME_URL) ||
+      top_sites_[index].url.spec() ==
+      l10n_util::GetStringUTF8(IDS_THEMES_GALLERY_URL))
+    return;  // Don't need thumbnails for prepopulated URLs.
+
   migration_pending_urls_.insert(top_sites_[index].url);
 
   if (mock_history_service_) {
@@ -316,6 +494,9 @@ void TopSites::StartQueryForThumbnail(size_t index) {
     return;
   }
 
+  if (!profile_)
+    return;
+
   HistoryService* hs = profile_->GetHistoryService(Profile::EXPLICIT_ACCESS);
   // |hs| may be null during unit tests.
   if (!hs)
@@ -327,54 +508,81 @@ void TopSites::StartQueryForThumbnail(size_t index) {
   cancelable_consumer_.SetClientData(hs, handle, index);
 }
 
-void TopSites::StoreMostVisited(MostVisitedURLList* most_visited) {
-  DCHECK(ChromeThread::CurrentlyOn(ChromeThread::DB));
-  // Take ownership of the most visited data.
-  top_sites_.clear();
-  top_sites_.swap(*most_visited);
-  waiting_for_results_ = false;
-
-  // Save the redirect information for quickly mapping to the canonical URLs.
+void TopSites::GenerateCanonicalURLs() {
+  lock_.AssertAcquired();
   canonical_urls_.clear();
   for (size_t i = 0; i < top_sites_.size(); i++) {
     const MostVisitedURL& mv = top_sites_[i];
     StoreRedirectChain(mv.redirects, i);
+  }
+}
+
+void TopSites::StoreMostVisited(MostVisitedURLList* most_visited) {
+  DCHECK(ChromeThread::CurrentlyOn(ChromeThread::DB));
+  MostVisitedURLList filtered_urls;
+  PendingCallbackSet callbacks;
+  {
+    AutoLock lock(lock_);
+    top_sites_.clear();
+    // Take ownership of the most visited data.
+    top_sites_.swap(*most_visited);
+    waiting_for_results_ = false;
 
-    std::map<GURL, Images>::iterator it = temp_thumbnails_map_.begin();
-    GURL canonical_url = GetCanonicalURL(mv.url);
-    for (; it != temp_thumbnails_map_.end(); it++) {
-      // Must map all temp URLs to canonical ones.
-      // temp_thumbnails_map_ contains non-canonical URLs, because
-      // when we add a temp thumbnail, redirect chain is not known.
-      // This is slow, but temp_thumbnails_map_ should have very few URLs.
-      if (canonical_url == GetCanonicalURL(it->first)) {
-        SetPageThumbnail(mv.url, it->second.thumbnail,
-                         it->second.thumbnail_score);
-        temp_thumbnails_map_.erase(it);
-        break;
+    // Save the redirect information for quickly mapping to the canonical URLs.
+    GenerateCanonicalURLs();
+
+    for (size_t i = 0; i < top_sites_.size(); i++) {
+      const MostVisitedURL& mv = top_sites_[i];
+      std::map<GURL, Images>::iterator it = temp_thumbnails_map_.begin();
+      GURL canonical_url = GetCanonicalURL(mv.url);
+      for (; it != temp_thumbnails_map_.end(); it++) {
+        // Must map all temp URLs to canonical ones.
+        // temp_thumbnails_map_ contains non-canonical URLs, because
+        // when we add a temp thumbnail, redirect chain is not known.
+        // This is slow, but temp_thumbnails_map_ should have very few URLs.
+        if (canonical_url == GetCanonicalURL(it->first)) {
+          SetPageThumbnailEncoded(mv.url, it->second.thumbnail,
+                                  it->second.thumbnail_score);
+          temp_thumbnails_map_.erase(it);
+          break;
+        }
       }
     }
-  }
-  if (top_sites_.size() >= kTopSitesNumber)
-    temp_thumbnails_map_.clear();
+    if (top_sites_.size() >= kTopSitesNumber)
+      temp_thumbnails_map_.clear();
+
+    if (pending_callbacks_.empty())
+      return;
+
+    ApplyBlacklistAndPinnedURLs(top_sites_, &filtered_urls);
+    callbacks.swap(pending_callbacks_);
+  }  // lock_ is released.
+  // Process callbacks outside the lock - ForwardResults may cause
+  // thread switches.
+  ProcessPendingCallbacks(callbacks, filtered_urls);
 }
 
 void TopSites::StoreRedirectChain(const RedirectList& redirects,
                                   size_t destination) {
+  lock_.AssertAcquired();
   if (redirects.empty()) {
     NOTREACHED();
     return;
   }
 
   // Map all the redirected URLs to the destination.
-  for (size_t i = 0; i < redirects.size(); i++)
-    canonical_urls_[redirects[i]] = destination;
+  for (size_t i = 0; i < redirects.size(); i++) {
+    // If this redirect is already known, don't replace it with a new one.
+    if (canonical_urls_.find(redirects[i]) == canonical_urls_.end())
+      canonical_urls_[redirects[i]] = destination;
+  }
 }
 
 GURL TopSites::GetCanonicalURL(const GURL& url) const {
+  lock_.AssertAcquired();
   std::map<GURL, size_t>::const_iterator found = canonical_urls_.find(url);
   if (found == canonical_urls_.end())
-    return GURL();  // Don't know anything about this URL.
+    return url;  // Unknown URL - return unchanged.
   return top_sites_[found->second].url;
 }
 
@@ -435,16 +643,19 @@ void TopSites::StartQueryForMostVisited() {
     // Testing with a mockup.
     // QueryMostVisitedURLs is not virtual, so we have to duplicate the code.
     mock_history_service_->QueryMostVisitedURLs(
-        kTopSitesNumber,
+        kTopSitesNumber + blacklist_->size(),
         kDaysOfHistory,
         &cancelable_consumer_,
         NewCallback(this, &TopSites::OnTopSitesAvailable));
   } else {
+    if (!profile_)
+      return;
+
     HistoryService* hs = profile_->GetHistoryService(Profile::EXPLICIT_ACCESS);
     // |hs| may be null during unit tests.
     if (hs) {
       hs->QueryMostVisitedURLs(
-          kTopSitesNumber,
+          kTopSitesNumber + blacklist_->size(),
           kDaysOfHistory,
           &cancelable_consumer_,
           NewCallback(this, &TopSites::OnTopSitesAvailable));
@@ -455,11 +666,106 @@ void TopSites::StartQueryForMostVisited() {
 }
 
 void TopSites::StartMigration() {
+  LOG(INFO) << "Starting migration to TopSites.";
   migration_in_progress_ = true;
   StartQueryForMostVisited();
+  MigratePinnedURLs();
+}
+
+bool TopSites::HasBlacklistedItems() const {
+  AutoLock lock(lock_);
+  return !blacklist_->empty();
+}
+
+void TopSites::AddBlacklistedURL(const GURL& url) {
+  AutoLock lock(lock_);
+  RemovePinnedURLLocked(url);
+  Value* dummy = Value::CreateNullValue();
+  blacklist_->SetWithoutPathExpansion(GetURLHash(url), dummy);
+}
+
+bool TopSites::IsBlacklisted(const GURL& url) {
+  lock_.AssertAcquired();
+  bool result = blacklist_->HasKey(GetURLHash(url));
+  return result;
+}
+
+void TopSites::RemoveBlacklistedURL(const GURL& url) {
+  AutoLock lock(lock_);
+  blacklist_->RemoveWithoutPathExpansion(GetURLHash(url), NULL);
+}
+
+void TopSites::ClearBlacklistedURLs() {
+  blacklist_->Clear();
+}
+
+void TopSites::AddPinnedURL(const GURL& url, size_t pinned_index) {
+  GURL old;
+  if (GetPinnedURLAtIndex(pinned_index, &old)) {
+    RemovePinnedURL(old);
+  }
+
+  if (IsURLPinned(url)) {
+    RemovePinnedURL(url);
+  }
+
+  Value* index = Value::CreateIntegerValue(pinned_index);
+  AutoLock lock(lock_);
+  pinned_urls_->SetWithoutPathExpansion(GetURLString(url), index);
+}
+
+void TopSites::RemovePinnedURL(const GURL& url) {
+  AutoLock lock(lock_);
+  RemovePinnedURLLocked(url);
+}
+
+void TopSites::RemovePinnedURLLocked(const GURL& url) {
+  lock_.AssertAcquired();
+  pinned_urls_->RemoveWithoutPathExpansion(GetURLString(url), NULL);
+}
+
+bool TopSites::IsURLPinned(const GURL& url) {
+  AutoLock lock(lock_);
+  int tmp;
+  bool result = pinned_urls_->GetIntegerWithoutPathExpansion(
+      GetURLString(url), &tmp);
+  return result;
+}
+
+bool TopSites::GetPinnedURLAtIndex(size_t index, GURL* url) {
+  for (DictionaryValue::key_iterator it = pinned_urls_->begin_keys();
+       it != pinned_urls_->end_keys(); ++it) {
+    int current_index;
+    if (pinned_urls_->GetIntegerWithoutPathExpansion(*it, &current_index)) {
+      if (static_cast<size_t>(current_index) == index) {
+        *url = GURL(*it);
+        return true;
+      }
+    }
+  }
+  return false;
+}
+
+// static
+void TopSites::DeleteTopSites(scoped_refptr<TopSites>& ptr) {
+  if (!ptr.get() || !MessageLoop::current())
+    return;
+  if (ChromeThread::IsWellKnownThread(ChromeThread::UI)) {
+    ptr = NULL;
+  } else {
+    // Need to roll our own UI thread.
+    ChromeThread ui_loop(ChromeThread::UI, MessageLoop::current());
+    ptr = NULL;
+    MessageLoop::current()->RunAllPending();
+  }
+}
+
+void TopSites::ClearProfile() {
+  profile_ = NULL;
 }
 
 base::TimeDelta TopSites::GetUpdateDelay() {
+  AutoLock lock(lock_);
   if (top_sites_.size() == 0)
     return base::TimeDelta::FromSeconds(30);
 
@@ -472,29 +778,36 @@ base::TimeDelta TopSites::GetUpdateDelay() {
 void TopSites::OnTopSitesAvailable(
     CancelableRequestProvider::Handle handle,
     MostVisitedURLList pages) {
-  if (!pending_callbacks_.empty()) {
-    PendingCallbackSet copy(pending_callbacks_);
-    PendingCallbackSet::iterator i;
-    for (i = pending_callbacks_.begin();
-         i != pending_callbacks_.end(); ++i) {
-      scoped_refptr<CancelableRequest<GetTopSitesCallback> > request = *i;
-      if (!request->canceled())
-        request->ForwardResult(GetTopSitesCallback::TupleType(pages));
-    }
-    pending_callbacks_.clear();
-  }
-
+  AddPrepopulatedPages(&pages);
   ChromeThread::PostTask(ChromeThread::DB, FROM_HERE, NewRunnableMethod(
       this, &TopSites::UpdateMostVisited, pages));
 }
 
+// static
+void TopSites::ProcessPendingCallbacks(PendingCallbackSet pending_callbacks,
+                                       const MostVisitedURLList& urls) {
+  PendingCallbackSet::iterator i;
+  for (i = pending_callbacks.begin();
+       i != pending_callbacks.end(); ++i) {
+    scoped_refptr<CancelableRequest<GetTopSitesCallback> > request = *i;
+    if (!request->canceled())
+      request->ForwardResult(GetTopSitesCallback::TupleType(urls));
+  }
+  pending_callbacks.clear();
+}
+
 void TopSites::OnThumbnailAvailable(CancelableRequestProvider::Handle handle,
                                     scoped_refptr<RefCountedBytes> thumbnail) {
   size_t index;
   if (mock_history_service_) {
     index = handle;
   } else {
+    if (!profile_)
+      return;
+
     HistoryService* hs = profile_ ->GetHistoryService(Profile::EXPLICIT_ACCESS);
+    if (!hs)
+      return;
     index = cancelable_consumer_.GetClientData(hs, handle);
   }
   DCHECK(static_cast<size_t>(index) < top_sites_.size());
@@ -504,7 +817,8 @@ void TopSites::OnThumbnailAvailable(CancelableRequestProvider::Handle handle,
 
   if (thumbnail.get() && thumbnail->size()) {
     const MostVisitedURL& url = top_sites_[index];
-    SetPageThumbnail(url.url, thumbnail, ThumbnailScore());
+    AutoLock lock(lock_);
+    SetPageThumbnailEncoded(url.url, thumbnail, ThumbnailScore());
   }
 
   if (migration_in_progress_ && migration_pending_urls_.empty() &&
@@ -519,6 +833,7 @@ void TopSites::SetMockHistoryService(MockHistoryService* mhs) {
 void TopSites::Observe(NotificationType type,
                        const NotificationSource& source,
                        const NotificationDetails& details) {
+  AutoLock lock(lock_);
   if (type == NotificationType::HISTORY_URLS_DELETED) {
     Details<history::URLsDeletedDetails> deleted_details(details);
     if (deleted_details->all_history) {
@@ -526,25 +841,34 @@ void TopSites::Observe(NotificationType type,
       ChromeThread::PostTask(ChromeThread::DB, FROM_HERE,
                              NewRunnableMethod(this, &TopSites::ResetDatabase));
     } else {
+      std::set<size_t> indices_to_delete;  // Indices into top_sites_.
       std::set<GURL>::iterator it;
       for (it = deleted_details->urls.begin();
            it != deleted_details->urls.end(); ++it) {
-        for (size_t i = 0; i < top_sites_.size(); i++) {
-          if (top_sites_[i].url == *it) {
-            top_sites_.erase(top_sites_.begin() + i);
-            break;
-          }
-        }
+        std::map<GURL,size_t>::const_iterator found = canonical_urls_.find(*it);
+        if (found != canonical_urls_.end())
+          indices_to_delete.insert(found->second);
+      }
+
+      for (std::set<size_t>::reverse_iterator i = indices_to_delete.rbegin();
+           i != indices_to_delete.rend(); i++) {
+        size_t index = *i;
+        RemovePinnedURLLocked(top_sites_[index].url);
+        top_sites_.erase(top_sites_.begin() + index);
       }
     }
+    // Canonical URLs are not valid any more.
+    GenerateCanonicalURLs();
     StartQueryForMostVisited();
   } else if (type == NotificationType::NAV_ENTRY_COMMITTED) {
     if (top_sites_.size() < kTopSitesNumber) {
-      const NavigationController::LoadCommittedDetails& load_details =
-          *Details<NavigationController::LoadCommittedDetails>(details).ptr();
-      GURL url = load_details.entry->url();
+      NavigationController::LoadCommittedDetails* load_details =
+          Details<NavigationController::LoadCommittedDetails>(details).ptr();
+      if (!load_details)
+        return;
+      GURL url = load_details->entry->url();
       if (canonical_urls_.find(url) == canonical_urls_.end() &&
-           HistoryService::CanAddURL(url)) {
+          HistoryService::CanAddURL(url)) {
         // Add this page to the known pages in case the thumbnail comes
         // in before we get the results.
         MostVisitedURL mv;
diff --git a/chrome/browser/history/top_sites.h b/chrome/browser/history/top_sites.h
index 4cc6059..c491066 100644
--- a/chrome/browser/history/top_sites.h
+++ b/chrome/browser/history/top_sites.h
@@ -4,6 +4,7 @@
 
 #ifndef CHROME_BROWSER_HISTORY_TOP_SITES_H_
 #define CHROME_BROWSER_HISTORY_TOP_SITES_H_
+#pragma once
 
 #include <map>
 #include <set>
@@ -17,6 +18,7 @@
 #include "base/ref_counted.h"
 #include "base/ref_counted_memory.h"
 #include "chrome/browser/cancelable_request.h"
+#include "chrome/browser/chrome_thread.h"
 #include "chrome/browser/history/history_types.h"
 #include "chrome/browser/history/history.h"
 #include "chrome/browser/history/page_usage_data.h"
@@ -24,6 +26,7 @@
 #include "chrome/common/thumbnail_score.h"
 #include "googleurl/src/gurl.h"
 
+class DictionaryValue;
 class SkBitmap;
 class Profile;
 
@@ -45,12 +48,17 @@ typedef std::vector<MostVisitedURL> MostVisitedURLList;
 // new tab page requests on the I/O thread without proxying to the UI thread is
 // a nontrivial performance win, especially when the browser is starting and
 // the UI thread is busy.
-class TopSites : public NotificationObserver,
-                 public base::RefCountedThreadSafe<TopSites>,
-                 public CancelableRequestProvider {
+class TopSites :
+      public base::RefCountedThreadSafe<TopSites,
+                                        ChromeThread::DeleteOnUIThread>,
+      public NotificationObserver,
+      public CancelableRequestProvider {
  public:
   explicit TopSites(Profile* profile);
 
+  // Returns whether top sites is enabled.
+  static bool IsEnabled();
+
   class MockHistoryService {
     // A mockup of a HistoryService used for testing TopSites.
    public:
@@ -66,14 +74,6 @@ class TopSites : public NotificationObserver,
         size_t index) = 0;
   };
 
-  struct Images {
-    scoped_refptr<RefCountedBytes> thumbnail;
-    ThumbnailScore thumbnail_score;
-
-    // TODO(brettw): this will eventually store the favicon.
-    // scoped_refptr<RefCountedBytes> favicon;
-  };
-
   // Initializes TopSites.
   void Init(const FilePath& db_name);
 
@@ -85,7 +85,9 @@ class TopSites : public NotificationObserver,
                         const ThumbnailScore& score);
 
   // Callback for GetMostVisitedURLs.
-  typedef Callback1<const MostVisitedURLList&>::Type GetTopSitesCallback;
+  typedef Callback1<MostVisitedURLList>::Type GetTopSitesCallback;
+  typedef std::set<scoped_refptr<CancelableRequest<GetTopSitesCallback> > >
+      PendingCallbackSet;
 
   // Returns a list of most visited URLs via a callback.
   // NOTE: the callback may be called immediately if we have the data cached.
@@ -101,18 +103,63 @@ class TopSites : public NotificationObserver,
   // Start reading thumbnails from the ThumbnailDatabase.
   void StartMigration();
 
+  // Blacklisted URLs
+
+  // Returns true if there is at least one item in the blacklist.
+  bool HasBlacklistedItems() const;
+
+  // Add a  URL to the blacklist.
+  void AddBlacklistedURL(const GURL& url);
+
+  // Removes a URL from the blacklist.
+  void RemoveBlacklistedURL(const GURL& url);
+
+  // Clear the blacklist.
+  void ClearBlacklistedURLs();
+
+  // Pinned URLs
+
+  // Pin a URL at |index|.
+  void AddPinnedURL(const GURL& url, size_t index);
+
+  // Returns true if a URL is pinned.
+  bool IsURLPinned(const GURL& url);
+
+  // Unpin a URL.
+  void RemovePinnedURL(const GURL& url);
+
+  // Return a URL pinned at |index| via |out|. Returns true if there
+  // is a URL pinned at |index|.
+  bool GetPinnedURLAtIndex(size_t index, GURL* out);
+
+  // TopSites must be deleted on a UI thread. This happens
+  // automatically in a real browser, but in unit_tests we don't have
+  // a real UI thread. Use this function to delete a TopSites object.
+  static void DeleteTopSites(scoped_refptr<TopSites>& ptr);
+
+  // Sets the profile pointer to NULL. This is for the case where
+  // TopSites outlives the profile, since TopSites is refcounted.
+  void ClearProfile();
+
  private:
-  friend class base::RefCountedThreadSafe<TopSites>;
+  friend struct ChromeThread::DeleteOnThread<ChromeThread::UI>;
+  friend class DeleteTask<TopSites>;
   friend class TopSitesTest;
   FRIEND_TEST_ALL_PREFIXES(TopSitesTest, GetMostVisited);
   FRIEND_TEST_ALL_PREFIXES(TopSitesTest, RealDatabase);
   FRIEND_TEST_ALL_PREFIXES(TopSitesTest, MockDatabase);
   FRIEND_TEST_ALL_PREFIXES(TopSitesTest, DeleteNotifications);
+  FRIEND_TEST_ALL_PREFIXES(TopSitesTest, PinnedURLsDeleted);
   FRIEND_TEST_ALL_PREFIXES(TopSitesTest, GetUpdateDelay);
   FRIEND_TEST_ALL_PREFIXES(TopSitesTest, Migration);
   FRIEND_TEST_ALL_PREFIXES(TopSitesTest, QueueingRequestsForTopSites);
   FRIEND_TEST_ALL_PREFIXES(TopSitesTest, CancelingRequestsForTopSites);
   FRIEND_TEST_ALL_PREFIXES(TopSitesTest, AddTemporaryThumbnail);
+  FRIEND_TEST_ALL_PREFIXES(TopSitesTest, Blacklisting);
+  FRIEND_TEST_ALL_PREFIXES(TopSitesTest, PinnedURLs);
+  FRIEND_TEST_ALL_PREFIXES(TopSitesTest, BlacklistingAndPinnedURLs);
+  FRIEND_TEST_ALL_PREFIXES(TopSitesTest, AddPrepopulatedPages);
+  FRIEND_TEST_ALL_PREFIXES(TopSitesTest, GetPageThumbnail);
 
   ~TopSites();
 
@@ -125,9 +172,9 @@ class TopSites : public NotificationObserver,
 
   // A version of SetPageThumbnail that takes RefCountedBytes as
   // returned by HistoryService.
-  bool SetPageThumbnail(const GURL& url,
-                        const RefCountedBytes* thumbnail,
-                        const ThumbnailScore& score);
+  bool SetPageThumbnailEncoded(const GURL& url,
+                               const RefCountedBytes* thumbnail,
+                               const ThumbnailScore& score);
 
   // Query history service for the list of available thumbnails.
   void StartQueryForMostVisited();
@@ -140,10 +187,17 @@ class TopSites : public NotificationObserver,
   void OnTopSitesAvailable(CancelableRequestProvider::Handle handle,
                            MostVisitedURLList data);
 
+  // Returns a list of urls to each pending callback.
+  static void ProcessPendingCallbacks(PendingCallbackSet pending_callbacks,
+                                      const MostVisitedURLList& urls);
+
   // Called when history service returns a thumbnail.
   void OnThumbnailAvailable(CancelableRequestProvider::Handle handle,
                             scoped_refptr<RefCountedBytes> thumbnail);
 
+  // Sets canonical_urls_ from top_sites_.
+  void GenerateCanonicalURLs();
+
   // Saves the set of the top URLs visited by this user. The 0th item is the
   // most popular.
   // DANGER! This will clear all data from the input argument.
@@ -186,6 +240,12 @@ class TopSites : public NotificationObserver,
                        const NotificationSource& source,
                        const NotificationDetails& details);
 
+  // Returns true if the URL is blacklisted.
+  bool IsBlacklisted(const GURL& url);
+
+  // A variant of RemovePinnedURL that must be called within a lock.
+  void RemovePinnedURLLocked(const GURL& url);
+
   // Returns the delay until the next update of history is needed.
   // Uses num_urls_changed
   base::TimeDelta GetUpdateDelay();
@@ -200,7 +260,7 @@ class TopSites : public NotificationObserver,
   // Write a thumbnail to database.
   void WriteThumbnailToDB(const MostVisitedURL& url,
                           int url_rank,
-                          const TopSites::Images& thumbnail);
+                          const Images& thumbnail);
 
   // Updates the top sites list and writes the difference to disk.
   void UpdateMostVisited(MostVisitedURLList most_visited);
@@ -216,6 +276,25 @@ class TopSites : public NotificationObserver,
                              const RefCountedBytes* thumbnail,
                              const ThumbnailScore& score);
 
+  // Add prepopulated pages: 'welcome to Chrome' and themes gallery.
+  // Returns true if any pages were added.
+  bool AddPrepopulatedPages(MostVisitedURLList* urls);
+
+  // Convert pinned_urls_ dictionary to the new format. Use URLs as
+  // dictionary keys.
+  void MigratePinnedURLs();
+
+  // Takes |urls|, produces it's copy in |out| after removing
+  // blacklisted URLs and reordering pinned URLs.
+  void ApplyBlacklistAndPinnedURLs(const MostVisitedURLList& urls,
+                                   MostVisitedURLList* out);
+
+  // Converts a url into a canonical string representation.
+  std::string GetURLString(const GURL& url);
+
+  // Returns an MD5 hash of the URL. Hashing is required for blacklisted URLs.
+  std::string GetURLHash(const GURL& url);
+
   Profile* profile_;
   // A mockup to use for testing. If NULL, use the real HistoryService
   // from the profile_. See SetMockHistoryService.
@@ -257,8 +336,6 @@ class TopSites : public NotificationObserver,
   // The map of requests for the top sites list. Can only be
   // non-empty at startup. After we read the top sites from the DB, we'll
   // always have a cached list.
-  typedef std::set<scoped_refptr<CancelableRequest<GetTopSitesCallback> > >
-      PendingCallbackSet;
   PendingCallbackSet pending_callbacks_;
 
   // Are we waiting for the top sites from HistoryService?
@@ -270,8 +347,20 @@ class TopSites : public NotificationObserver,
   // UpdateMostVisitedURLs call.
   std::map<GURL, Images> temp_thumbnails_map_;
 
-  // TODO(brettw): use the blacklist.
-  // std::set<GURL> blacklist_;
+  // Blacklisted and pinned URLs are stored in Preferences.
+
+  // Blacklisted URLs. They are filtered out from the list of Top
+  // Sites when GetMostVisitedURLs is called. Note that we are still
+  // storing all URLs, but filtering on access. It is a dictionary,
+  // key is the URL, value is a dummy value. This is owned by the
+  // PrefService.
+  DictionaryValue* blacklist_;
+
+  // This is a dictionary for the pinned URLs for the the most visited
+  // part of the new tab page. Key is the URL, value is
+  // index where it is pinned at (may be the same as key). This is
+  // owned by the PrefService.
+  DictionaryValue* pinned_urls_;
 
   DISALLOW_COPY_AND_ASSIGN(TopSites);
 };
diff --git a/chrome/browser/history/top_sites_database.cc b/chrome/browser/history/top_sites_database.cc
index 99f0bb4..05a588a 100644
--- a/chrome/browser/history/top_sites_database.cc
+++ b/chrome/browser/history/top_sites_database.cc
@@ -5,6 +5,7 @@
 #include "app/sql/transaction.h"
 #include "base/string_util.h"
 #include "chrome/browser/diagnostics/sqlite_diagnostics.h"
+#include "chrome/browser/history/history_types.h"
 #include "chrome/browser/history/top_sites.h"
 #include "chrome/browser/history/top_sites_database.h"
 
@@ -13,6 +14,9 @@ namespace history {
 TopSitesDatabaseImpl::TopSitesDatabaseImpl() {
 }
 
+TopSitesDatabaseImpl::~TopSitesDatabaseImpl() {
+}
+
 bool TopSitesDatabaseImpl::Init(const FilePath& db_name) {
   // Settings copied from ThumbnailDatabase.
   db_.set_error_delegate(GetErrorHandlerForThumbnailDb());
@@ -48,7 +52,7 @@ bool TopSitesDatabaseImpl::InitThumbnailTable() {
 
 void TopSitesDatabaseImpl::GetPageThumbnails(MostVisitedURLList* urls,
                                              std::map<GURL,
-                                             TopSites::Images>* thumbnails) {
+                                             Images>* thumbnails) {
   sql::Statement statement(db_.GetCachedStatement(
       SQL_FROM_HERE,
       "SELECT url, url_rank, title, thumbnail, redirects, "
@@ -75,7 +79,7 @@ void TopSitesDatabaseImpl::GetPageThumbnails(MostVisitedURLList* urls,
 
     std::vector<unsigned char> data;
     statement.ColumnBlobAsVector(3, &data);
-    TopSites::Images thumbnail;
+    Images thumbnail;
     thumbnail.thumbnail = RefCountedBytes::TakeVector(&data);
     thumbnail.thumbnail_score.boring_score = statement.ColumnDouble(5);
     thumbnail.thumbnail_score.good_clipping = statement.ColumnBool(6);
@@ -106,7 +110,7 @@ void TopSitesDatabaseImpl::SetRedirects(const std::string& redirects,
 
 void TopSitesDatabaseImpl::SetPageThumbnail(const MostVisitedURL& url,
                                             int new_rank,
-                                            const TopSites::Images& thumbnail) {
+                                            const Images& thumbnail) {
   sql::Transaction transaction(&db_);
   transaction.Begin();
 
@@ -122,7 +126,7 @@ void TopSitesDatabaseImpl::SetPageThumbnail(const MostVisitedURL& url,
 }
 
 void TopSitesDatabaseImpl::UpdatePageThumbnail(
-    const MostVisitedURL& url, const TopSites::Images& thumbnail) {
+    const MostVisitedURL& url, const Images& thumbnail) {
   sql::Statement statement(db_.GetCachedStatement(
       SQL_FROM_HERE,
       "UPDATE thumbnails SET "
@@ -150,7 +154,7 @@ void TopSitesDatabaseImpl::UpdatePageThumbnail(
 
 void TopSitesDatabaseImpl::AddPageThumbnail(const MostVisitedURL& url,
                                             int new_rank,
-                                            const TopSites::Images& thumbnail) {
+                                            const Images& thumbnail) {
   int count = GetRowCount();
 
   sql::Statement statement(db_.GetCachedStatement(
@@ -194,7 +198,7 @@ void TopSitesDatabaseImpl::UpdatePageRankNoTransaction(
     const MostVisitedURL& url, int new_rank) {
   int prev_rank = GetURLRank(url);
   if (prev_rank == -1) {
-    NOTREACHED() << "Updating rank of an unknown URL: " << url.url.spec();
+    LOG(WARNING) << "Updating rank of an unknown URL: " << url.url.spec();
     return;
   }
 
@@ -236,7 +240,7 @@ void TopSitesDatabaseImpl::UpdatePageRankNoTransaction(
 }
 
 bool TopSitesDatabaseImpl::GetPageThumbnail(const GURL& url,
-                                            TopSites::Images* thumbnail) {
+                                            Images* thumbnail) {
   sql::Statement statement(db_.GetCachedStatement(
       SQL_FROM_HERE,
       "SELECT thumbnail, boring_score, good_clipping, at_top, last_updated "
diff --git a/chrome/browser/history/top_sites_database.h b/chrome/browser/history/top_sites_database.h
index cfb362c..edfb4e5 100644
--- a/chrome/browser/history/top_sites_database.h
+++ b/chrome/browser/history/top_sites_database.h
@@ -4,20 +4,19 @@
 
 #ifndef CHROME_BROWSER_HISTORY_TOP_SITES_DATABASE_H_
 #define CHROME_BROWSER_HISTORY_TOP_SITES_DATABASE_H_
+#pragma once
 
 #include <map>
 #include <string>
-#include <vector>
 
 #include "app/sql/connection.h"
 #include "base/ref_counted.h"
-#include "chrome/browser/history/history_types.h"
 #include "chrome/browser/history/url_database.h"  // For DBCloseScoper.
 
 class FilePath;
 class RefCountedMemory;
 class SkBitmap;
-class TopSites;
+class Images;
 
 namespace base {
 class Time;
@@ -37,7 +36,7 @@ class TopSitesDatabase {
   // Returns a list of all URLs currently in the table.
   virtual void GetPageThumbnails(MostVisitedURLList* urls,
                                  std::map<GURL,
-                                 TopSites::Images>* thumbnails) = 0;
+                                 Images>* thumbnails) = 0;
 
   // Set a thumbnail for a URL. |url_rank| is the position of the URL
   // in the list of TopURLs, zero-based.
@@ -45,20 +44,20 @@ class TopSitesDatabase {
   // thumbnail.
   virtual void SetPageThumbnail(const MostVisitedURL& url,
                                 int url_rank,
-                                const TopSites::Images& thumbnail) = 0;
+                                const Images& thumbnail) = 0;
 
   // Update rank of a URL that's already in the database.
   virtual void UpdatePageRank(const MostVisitedURL& url, int new_rank) = 0;
 
   // Convenience wrapper.
   bool GetPageThumbnail(const MostVisitedURL& url,
-                        TopSites::Images* thumbnail) {
+                        Images* thumbnail) {
     return GetPageThumbnail(url.url, thumbnail);
   }
 
   // Get a thumbnail for a given page. Returns true iff we have the thumbnail.
   virtual bool GetPageThumbnail(const GURL& url,
-                                TopSites::Images* thumbnail) = 0;
+                                Images* thumbnail) = 0;
 
   // Remove the record for this URL. Returns true iff removed successfully.
   virtual bool RemoveURL(const MostVisitedURL& url) = 0;
@@ -67,7 +66,7 @@ class TopSitesDatabase {
 class TopSitesDatabaseImpl : public TopSitesDatabase {
  public:
   TopSitesDatabaseImpl();
-  ~TopSitesDatabaseImpl() {}
+  virtual ~TopSitesDatabaseImpl();
 
   // Must be called after creation but before any other methods are called.
   // Returns true on success. If false, no other functions should be called.
@@ -78,7 +77,7 @@ class TopSitesDatabaseImpl : public TopSitesDatabase {
   // Returns a list of all URLs currently in the table.
   // WARNING: clears both input arguments.
   virtual void GetPageThumbnails(MostVisitedURLList* urls,
-                                 std::map<GURL, TopSites::Images>* thumbnails);
+                                 std::map<GURL, Images>* thumbnails);
 
   // Set a thumbnail for a URL. |url_rank| is the position of the URL
   // in the list of TopURLs, zero-based.
@@ -86,7 +85,7 @@ class TopSitesDatabaseImpl : public TopSitesDatabase {
   // thumbnail and rank. Shift the ranks of other URLs if necessary.
   virtual void SetPageThumbnail(const MostVisitedURL& url,
                                 int new_rank,
-                                const TopSites::Images& thumbnail);
+                                const Images& thumbnail);
 
   // Sets the rank for a given URL. The URL must be in the database.
   // Use SetPageThumbnail if it's not.
@@ -94,7 +93,7 @@ class TopSitesDatabaseImpl : public TopSitesDatabase {
 
   // Get a thumbnail for a given page. Returns true iff we have the thumbnail.
   virtual bool GetPageThumbnail(const GURL& url,
-                                TopSites::Images* thumbnail);
+                                Images* thumbnail);
 
   // Remove the record for this URL. Returns true iff removed successfully.
   virtual bool RemoveURL(const MostVisitedURL& url);
@@ -107,14 +106,14 @@ class TopSitesDatabaseImpl : public TopSitesDatabase {
   // Adds a new URL to the database.
   void AddPageThumbnail(const MostVisitedURL& url,
                         int new_rank,
-                        const TopSites::Images& thumbnail);
+                        const Images& thumbnail);
 
   // Sets the page rank. Should be called within an open transaction.
   void UpdatePageRankNoTransaction(const MostVisitedURL& url, int new_rank);
 
   // Updates thumbnail of a URL that's already in the database.
   void UpdatePageThumbnail(const MostVisitedURL& url,
-                           const TopSites::Images& thumbnail);
+                           const Images& thumbnail);
 
   // Returns the URL's current rank or -1 if it is not present.
   int GetURLRank(const MostVisitedURL& url);
diff --git a/chrome/browser/history/top_sites_unittest.cc b/chrome/browser/history/top_sites_unittest.cc
index a6b7e7b..c327647 100644
--- a/chrome/browser/history/top_sites_unittest.cc
+++ b/chrome/browser/history/top_sites_unittest.cc
@@ -1,18 +1,27 @@
-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "app/l10n_util.h"
+#include "base/file_util.h"
 #include "base/scoped_temp_dir.h"
 #include "base/string_util.h"
+#include "base/utf_string_conversions.h"
+#include "base/values.h"
+#include "chrome/browser/chrome_thread.h"
 #include "chrome/browser/history/top_sites.h"
-#include "chrome/common/chrome_paths.h"
+#include "chrome/browser/dom_ui/most_visited_handler.h"
 #include "chrome/browser/history/history_marshaling.h"
 #include "chrome/browser/history/top_sites_database.h"
 #include "chrome/browser/history/history_notifications.h"
+#include "chrome/common/chrome_paths.h"
 #include "chrome/test/testing_profile.h"
 #include "chrome/tools/profiles/thumbnail-inl.h"
 #include "gfx/codec/jpeg_codec.h"
 #include "googleurl/src/gurl.h"
+#include "grit/chromium_strings.h"
+#include "grit/generated_resources.h"
+#include "grit/locale_settings.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 
@@ -38,6 +47,13 @@ class TopSitesTest : public testing::Test {
   RefCountedBytes* weewar_thumbnail() { return weewar_thumbnail_; }
   CancelableRequestConsumer* consumer() { return &consumer_; }
   size_t number_of_callbacks() {return number_of_callbacks_; }
+  // Prepopulated URLs - added at the back of TopSites.
+  GURL welcome_url() {
+    return GURL(l10n_util::GetStringUTF8(IDS_CHROME_WELCOME_URL));
+  }
+  GURL themes_url() {
+    return GURL(l10n_util::GetStringUTF8(IDS_THEMES_GALLERY_URL));
+  }
 
   virtual void SetUp() {
     profile_.reset(new TestingProfile);
@@ -61,12 +77,12 @@ class TopSitesTest : public testing::Test {
 
   virtual void TearDown() {
     profile_.reset();
-    top_sites_ = NULL;
+    TopSites::DeleteTopSites(top_sites_);
     EXPECT_TRUE(file_util::Delete(file_name_, false));
   }
 
   // Callback for TopSites::GetMostVisitedURLs.
-  void OnTopSitesAvailable(const history::MostVisitedURLList& data) {
+  void OnTopSitesAvailable(history::MostVisitedURLList data) {
     urls_ = data;
     number_of_callbacks_++;
   }
@@ -79,7 +95,6 @@ class TopSitesTest : public testing::Test {
   }
 
   void StoreMostVisited(std::vector<MostVisitedURL>* urls) {
-    AutoLock lock(top_sites_->lock_);  // The function asserts it's in the lock.
     top_sites_->StoreMostVisited(urls);
   }
 
@@ -92,6 +107,10 @@ class TopSitesTest : public testing::Test {
                               added_urls, deleted_urls, moved_urls);
   }
 
+  Lock& lock() {
+    return top_sites_->lock_;
+  }
+
  private:
   scoped_refptr<TopSites> top_sites_;
   MostVisitedURLList urls_;
@@ -108,6 +127,7 @@ class TopSitesTest : public testing::Test {
   DISALLOW_COPY_AND_ASSIGN(TopSitesTest);
 };
 
+
 // A mockup of a HistoryService used for testing TopSites.
 class MockHistoryServiceImpl : public TopSites::MockHistoryService {
  public:
@@ -151,7 +171,7 @@ class MockHistoryServiceImpl : public TopSites::MockHistoryService {
     MostVisitedURLList::iterator pos = std::find(most_visited_urls_.begin(),
                                                  most_visited_urls_.end(),
                                                  mvu);
-    EXPECT_TRUE(pos != most_visited_urls_.end());
+    EXPECT_TRUE(pos != most_visited_urls_.end()) << url.spec();
     scoped_refptr<RefCountedBytes> thumbnail;
     callback->Run(index, thumbnail);
     delete callback;
@@ -175,14 +195,14 @@ class MockHistoryServiceImpl : public TopSites::MockHistoryService {
 class MockTopSitesDatabaseImpl : public TopSitesDatabase {
  public:
   virtual void GetPageThumbnails(MostVisitedURLList* urls,
-                                 std::map<GURL, TopSites::Images>* thumbnails) {
+                                 std::map<GURL, Images>* thumbnails) {
     // Return a copy of the vector.
     *urls = top_sites_list_;
     *thumbnails = thumbnails_map_;
   }
 
   virtual void SetPageThumbnail(const MostVisitedURL& url, int url_rank,
-                                const TopSites::Images& thumbnail) {
+                                const Images& thumbnail) {
     SetPageRank(url, url_rank);
     // Update thubmnail
     thumbnails_map_[url.url] = thumbnail;
@@ -216,8 +236,8 @@ class MockTopSitesDatabaseImpl : public TopSitesDatabase {
 
   // Get a thumbnail for a given page. Returns true iff we have the thumbnail.
   virtual bool GetPageThumbnail(const GURL& url,
-                                TopSites::Images* thumbnail) {
-    std::map<GURL, TopSites::Images>::const_iterator found =
+                                Images* thumbnail) {
+    std::map<GURL, Images>::const_iterator found =
         thumbnails_map_.find(url);
     if (found == thumbnails_map_.end())
       return false;  // No thumbnail for this URL.
@@ -242,7 +262,7 @@ class MockTopSitesDatabaseImpl : public TopSitesDatabase {
 
  private:
   MostVisitedURLList top_sites_list_;  // Keeps the URLs sorted by score (rank).
-  std::map<GURL, TopSites::Images> thumbnails_map_;
+  std::map<GURL, Images> thumbnails_map_;
 };
 
 
@@ -294,9 +314,9 @@ TEST_F(TopSitesTest, GetCanonicalURL) {
   AppendMostVisitedURL(&most_visited, news);
   StoreMostVisited(&most_visited);
 
-  // Random URLs not in the database shouldn't be reported as being in there.
+  // Random URLs not in the database are returned unchanged.
   GURL result = GetCanonicalURL(GURL("http://fark.com/"));
-  EXPECT_TRUE(result.is_empty());
+  EXPECT_EQ(GURL("http://fark.com/"), result);
 
   // Easy case, there are no redirects and the exact URL is stored.
   result = GetCanonicalURL(news);
@@ -395,6 +415,50 @@ TEST_F(TopSitesTest, SetPageThumbnail) {
   EXPECT_FALSE(top_sites().SetPageThumbnail(url1a, thumbnail, medium_score));
 }
 
+TEST_F(TopSitesTest, GetPageThumbnail) {
+  ChromeThread db_loop(ChromeThread::DB, MessageLoop::current());
+  MostVisitedURLList url_list;
+  MostVisitedURL url1 = {GURL("http://asdf.com")};
+  url1.redirects.push_back(url1.url);
+  url_list.push_back(url1);
+
+  MostVisitedURL url2 = {GURL("http://gmail.com")};
+  url2.redirects.push_back(url2.url);
+  url2.redirects.push_back(GURL("http://mail.google.com"));
+  url_list.push_back(url2);
+
+  top_sites().UpdateMostVisited(url_list);
+  MessageLoop::current()->RunAllPending();
+
+  // Create a dummy thumbnail.
+  SkBitmap thumbnail;
+  thumbnail.setConfig(SkBitmap::kARGB_8888_Config, 4, 4);
+  thumbnail.allocPixels();
+  thumbnail.eraseRGB(0x00, 0x00, 0x00);
+  ThumbnailScore score(0.5, true, true, base::Time::Now());
+
+  RefCountedBytes* result = NULL;
+  EXPECT_TRUE(top_sites().SetPageThumbnail(url1.url, thumbnail, score));
+  EXPECT_TRUE(top_sites().GetPageThumbnail(url1.url, &result));
+
+  EXPECT_TRUE(top_sites().SetPageThumbnail(GURL("http://gmail.com"),
+                                           thumbnail, score));
+  EXPECT_TRUE(top_sites().GetPageThumbnail(GURL("http://gmail.com"),
+                                           &result));
+  // Get a thumbnail via a redirect.
+  EXPECT_TRUE(top_sites().GetPageThumbnail(GURL("http://mail.google.com"),
+                                           &result));
+
+  EXPECT_TRUE(top_sites().SetPageThumbnail(GURL("http://mail.google.com"),
+                                           thumbnail, score));
+  EXPECT_TRUE(top_sites().GetPageThumbnail(url2.url, &result));
+
+  scoped_ptr<SkBitmap> out_bitmap(gfx::JPEGCodec::Decode(result->front(),
+                                                         result->size()));
+  EXPECT_EQ(0, memcmp(thumbnail.getPixels(), out_bitmap->getPixels(),
+                      thumbnail.getSize()));
+}
+
 TEST_F(TopSitesTest, GetMostVisited) {
   ChromeThread db_loop(ChromeThread::DB, MessageLoop::current());
   GURL news("http://news.google.com/");
@@ -411,9 +475,12 @@ TEST_F(TopSitesTest, GetMostVisited) {
       consumer(),
       NewCallback(static_cast<TopSitesTest*>(this),
                   &TopSitesTest::OnTopSitesAvailable));
-  ASSERT_EQ(2u, urls().size());
+  // 2 extra prepopulated URLs.
+  ASSERT_EQ(4u, urls().size());
   EXPECT_EQ(news, urls()[0].url);
   EXPECT_EQ(google, urls()[1].url);
+  EXPECT_EQ(welcome_url(), urls()[2].url);
+  EXPECT_EQ(themes_url(), urls()[3].url);
 }
 
 TEST_F(TopSitesTest, MockDatabase) {
@@ -432,7 +499,7 @@ TEST_F(TopSitesTest, MockDatabase) {
   url.url = asdf_url;
   url.title = asdf_title;
   url.redirects.push_back(url.url);
-  TopSites::Images thumbnail;
+  Images thumbnail;
   db->SetPageThumbnail(url, 0, thumbnail);
 
   top_sites().ReadDatabase();
@@ -441,9 +508,11 @@ TEST_F(TopSitesTest, MockDatabase) {
       consumer(),
       NewCallback(static_cast<TopSitesTest*>(this),
                   &TopSitesTest::OnTopSitesAvailable));
-  ASSERT_EQ(1u, urls().size());
+  ASSERT_EQ(3u, urls().size());
   EXPECT_EQ(asdf_url, urls()[0].url);
   EXPECT_EQ(asdf_title, urls()[0].title);
+  EXPECT_EQ(welcome_url(), urls()[1].url);
+  EXPECT_EQ(themes_url(), urls()[2].url);
 
   MostVisitedURL url2;
   url2.url = google_url;
@@ -459,11 +528,13 @@ TEST_F(TopSitesTest, MockDatabase) {
       consumer(),
       NewCallback(static_cast<TopSitesTest*>(this),
                   &TopSitesTest::OnTopSitesAvailable));
-  ASSERT_EQ(2u, urls().size());
+  ASSERT_EQ(4u, urls().size());
   EXPECT_EQ(google_url, urls()[0].url);
   EXPECT_EQ(google_title, urls()[0].title);
   EXPECT_EQ(asdf_url, urls()[1].url);
   EXPECT_EQ(asdf_title, urls()[1].title);
+  EXPECT_EQ(welcome_url(), urls()[2].url);
+  EXPECT_EQ(themes_url(), urls()[3].url);
 
   MockHistoryServiceImpl hs;
   // Add one old, one new URL to the history.
@@ -475,10 +546,10 @@ TEST_F(TopSitesTest, MockDatabase) {
   top_sites().StartQueryForMostVisited();
   MessageLoop::current()->RunAllPending();
 
-  std::map<GURL, TopSites::Images> thumbnails;
+  std::map<GURL, Images> thumbnails;
   MostVisitedURLList result;
   db->GetPageThumbnails(&result, &thumbnails);
-  ASSERT_EQ(2u, result.size());
+  ASSERT_EQ(4u, result.size());
   EXPECT_EQ(google_title, result[0].title);
   EXPECT_EQ(news_title, result[1].title);
 }
@@ -500,18 +571,18 @@ TEST_F(TopSitesTest, TopSitesDB) {
   url.url = asdf_url;
   url.title = asdf_title;
   url.redirects.push_back(url.url);
-  TopSites::Images thumbnail;
+  Images thumbnail;
   thumbnail.thumbnail = random_thumbnail();
   // Add asdf at rank 0.
   db.SetPageThumbnail(url, 0, thumbnail);
 
-  TopSites::Images result;
+  Images result;
   EXPECT_TRUE(db.GetPageThumbnail(url.url, &result));
   EXPECT_EQ(thumbnail.thumbnail->data.size(), result.thumbnail->data.size());
   EXPECT_TRUE(ThumbnailsAreEqual(thumbnail.thumbnail, result.thumbnail));
 
   MostVisitedURLList urls;
-  std::map<GURL, TopSites::Images> thumbnails;
+  std::map<GURL, Images> thumbnails;
   db.GetPageThumbnails(&urls, &thumbnails);
   ASSERT_EQ(1u, urls.size());
   EXPECT_EQ(asdf_url, urls[0].url);
@@ -587,7 +658,7 @@ TEST_F(TopSitesTest, RealDatabase) {
   url.url = asdf_url;
   url.title = asdf_title;
   url.redirects.push_back(url.url);
-  TopSites::Images thumbnail;
+  Images thumbnail;
   thumbnail.thumbnail = random_thumbnail();
   db->SetPageThumbnail(url, 0, thumbnail);
 
@@ -597,11 +668,13 @@ TEST_F(TopSitesTest, RealDatabase) {
       consumer(),
       NewCallback(static_cast<TopSitesTest*>(this),
                   &TopSitesTest::OnTopSitesAvailable));
-  ASSERT_EQ(1u, urls().size());
+  ASSERT_EQ(3u, urls().size());
   EXPECT_EQ(asdf_url, urls()[0].url);
   EXPECT_EQ(asdf_title, urls()[0].title);
+  EXPECT_EQ(welcome_url(), urls()[1].url);
+  EXPECT_EQ(themes_url(), urls()[2].url);
 
-  TopSites::Images img_result;
+  Images img_result;
   db->GetPageThumbnail(asdf_url, &img_result);
   EXPECT_TRUE(img_result.thumbnail != NULL);
   EXPECT_TRUE(ThumbnailsAreEqual(random_thumbnail(), img_result.thumbnail));
@@ -619,7 +692,7 @@ TEST_F(TopSitesTest, RealDatabase) {
   url2.redirects.push_back(google3_url);
 
   // Add new thumbnail at rank 0 and shift the other result to 1.
-  TopSites::Images g_thumbnail;
+  Images g_thumbnail;
   g_thumbnail.thumbnail = google_thumbnail();
   db->SetPageThumbnail(url2, 0, g_thumbnail);
 
@@ -629,7 +702,7 @@ TEST_F(TopSitesTest, RealDatabase) {
       consumer(),
       NewCallback(static_cast<TopSitesTest*>(this),
                   &TopSitesTest::OnTopSitesAvailable));
-  ASSERT_EQ(2u, urls().size());
+  ASSERT_EQ(4u, urls().size());
   EXPECT_EQ(google1_url, urls()[0].url);
   EXPECT_EQ(google_title, urls()[0].title);
   EXPECT_TRUE(top_sites().GetPageThumbnail(google1_url, &thumbnail_result));
@@ -641,6 +714,8 @@ TEST_F(TopSitesTest, RealDatabase) {
 
   EXPECT_EQ(asdf_url, urls()[1].url);
   EXPECT_EQ(asdf_title, urls()[1].title);
+  EXPECT_EQ(welcome_url(), urls()[2].url);
+  EXPECT_EQ(themes_url(), urls()[3].url);
 
   MockHistoryServiceImpl hs;
   // Add one old, one new URL to the history.
@@ -652,10 +727,10 @@ TEST_F(TopSitesTest, RealDatabase) {
   top_sites().StartQueryForMostVisited();
   MessageLoop::current()->RunAllPending();
 
-  std::map<GURL, TopSites::Images> thumbnails;
+  std::map<GURL, Images> thumbnails;
   MostVisitedURLList results;
   db->GetPageThumbnails(&results, &thumbnails);
-  ASSERT_EQ(2u, results.size());
+  ASSERT_EQ(4u, results.size());
   EXPECT_EQ(google_title, results[0].title);
   EXPECT_EQ(news_title, results[1].title);
 
@@ -673,7 +748,7 @@ TEST_F(TopSitesTest, RealDatabase) {
                                            *weewar_bitmap,
                                            medium_score));
   RefCountedBytes* out_1;
-  TopSites::Images out_2;
+  Images out_2;
   EXPECT_TRUE(top_sites().GetPageThumbnail(google1_url, &out_1));
 
   MessageLoop::current()->RunAllPending();
@@ -705,9 +780,7 @@ TEST_F(TopSitesTest, RealDatabase) {
   EXPECT_TRUE(high_score.Equals(out_2.thumbnail_score));
 }
 
-// This test has been crashing unit_tests on Mac 10.6.
-// See http://crbug.com/49799
-TEST_F(TopSitesTest, DISABLED_DeleteNotifications) {
+TEST_F(TopSitesTest, DeleteNotifications) {
   ChromeThread db_loop(ChromeThread::DB, MessageLoop::current());
   GURL google1_url("http://google.com");
   GURL google2_url("http://google.com/redirect");
@@ -731,35 +804,116 @@ TEST_F(TopSitesTest, DISABLED_DeleteNotifications) {
       consumer(),
       NewCallback(static_cast<TopSitesTest*>(this),
                   &TopSitesTest::OnTopSitesAvailable));
-  ASSERT_EQ(2u, urls().size());
+  // 2 extra prepopulated URLs.
+  ASSERT_EQ(4u, urls().size());
 
   hs.RemoveMostVisitedURL();
 
-  history::URLsDeletedDetails details;
-  details.all_history = false;
+  history::URLsDeletedDetails history_details;
+  history_details.all_history = false;
+  Details<URLsDeletedDetails> details(&history_details);
   top_sites().Observe(NotificationType::HISTORY_URLS_DELETED,
                       Source<Profile> (&profile()),
-                      (const NotificationDetails&)details);
+                      details);
   MessageLoop::current()->RunAllPending();
 
   top_sites().GetMostVisitedURLs(
       consumer(),
       NewCallback(static_cast<TopSitesTest*>(this),
                   &TopSitesTest::OnTopSitesAvailable));
-  ASSERT_EQ(1u, urls().size());
+  ASSERT_EQ(3u, urls().size());
   EXPECT_EQ(google_title, urls()[0].title);
+  EXPECT_EQ(welcome_url(), urls()[1].url);
+  EXPECT_EQ(themes_url(), urls()[2].url);
+
+  hs.RemoveMostVisitedURL();
+  history_details.all_history = true;
+  details = Details<HistoryDetails>(&history_details);
+  top_sites().Observe(NotificationType::HISTORY_URLS_DELETED,
+                      Source<Profile> (&profile()),
+                      details);
+  MessageLoop::current()->RunAllPending();
+  top_sites().GetMostVisitedURLs(
+      consumer(),
+      NewCallback(static_cast<TopSitesTest*>(this),
+                  &TopSitesTest::OnTopSitesAvailable));
+  ASSERT_EQ(2u, urls().size());
+  EXPECT_EQ(welcome_url(), urls()[0].url);
+  EXPECT_EQ(themes_url(), urls()[1].url);
+}
+
+TEST_F(TopSitesTest, PinnedURLsDeleted) {
+  ChromeThread db_loop(ChromeThread::DB, MessageLoop::current());
+  GURL google1_url("http://google.com");
+  GURL google2_url("http://google.com/redirect");
+  GURL google3_url("http://www.google.com");
+  string16 google_title(ASCIIToUTF16("Google"));
+  GURL news_url("http://news.google.com");
+  string16 news_title(ASCIIToUTF16("Google News"));
+
+  MockHistoryServiceImpl hs;
+
+  top_sites().Init(file_name());
+
+  hs.AppendMockPage(google1_url, google_title);
+  hs.AppendMockPage(news_url, news_title);
+  top_sites().SetMockHistoryService(&hs);
+
+  top_sites().StartQueryForMostVisited();
+  MessageLoop::current()->RunAllPending();
+  top_sites().GetMostVisitedURLs(
+      consumer(),
+      NewCallback(static_cast<TopSitesTest*>(this),
+                  &TopSitesTest::OnTopSitesAvailable));
+  MessageLoop::current()->RunAllPending();
+  EXPECT_EQ(1u, number_of_callbacks());
+  // 2 extra prepopulated URLs.
+  ASSERT_EQ(4u, urls().size());
+
+  top_sites().AddPinnedURL(news_url, 3);
+  EXPECT_TRUE(top_sites().IsURLPinned(news_url));
 
   hs.RemoveMostVisitedURL();
-  details.all_history = true;
+  history::URLsDeletedDetails history_details;
+  history_details.all_history = false;
+  history_details.urls.insert(news_url);
+  Details<URLsDeletedDetails> details(&history_details);
   top_sites().Observe(NotificationType::HISTORY_URLS_DELETED,
                       Source<Profile> (&profile()),
-                      (const NotificationDetails&)details);
+                      details);
   MessageLoop::current()->RunAllPending();
   top_sites().GetMostVisitedURLs(
       consumer(),
       NewCallback(static_cast<TopSitesTest*>(this),
                   &TopSitesTest::OnTopSitesAvailable));
-  ASSERT_EQ(0u, urls().size());
+  MessageLoop::current()->RunAllPending();
+  EXPECT_EQ(2u, number_of_callbacks());
+  ASSERT_EQ(3u, urls().size());
+  EXPECT_FALSE(top_sites().IsURLPinned(news_url));
+
+  hs.RemoveMostVisitedURL();
+  history_details.all_history = true;
+  details = Details<HistoryDetails>(&history_details);
+  top_sites().Observe(NotificationType::HISTORY_URLS_DELETED,
+                      Source<Profile> (&profile()),
+                      details);
+  MessageLoop::current()->RunAllPending();
+  top_sites().GetMostVisitedURLs(
+      consumer(),
+      NewCallback(static_cast<TopSitesTest*>(this),
+                  &TopSitesTest::OnTopSitesAvailable));
+  ASSERT_EQ(2u, urls().size());
+  MessageLoop::current()->RunAllPending();
+
+  top_sites().StartQueryForMostVisited();
+  MessageLoop::current()->RunAllPending();
+  top_sites().GetMostVisitedURLs(
+      consumer(),
+      NewCallback(static_cast<TopSitesTest*>(this),
+                  &TopSitesTest::OnTopSitesAvailable));
+  ASSERT_EQ(2u, urls().size());
+  EXPECT_EQ(welcome_url(), urls()[0].url);
+  EXPECT_EQ(themes_url(), urls()[1].url);
 }
 
 TEST_F(TopSitesTest, GetUpdateDelay) {
@@ -780,8 +934,6 @@ TEST_F(TopSitesTest, GetUpdateDelay) {
 TEST_F(TopSitesTest, Migration) {
   ChromeThread db_loop(ChromeThread::DB, MessageLoop::current());
   GURL google1_url("http://google.com");
-  GURL google2_url("http://google.com/redirect");
-  GURL google3_url("http://www.google.com");
   string16 google_title(ASCIIToUTF16("Google"));
   GURL news_url("http://news.google.com");
   string16 news_title(ASCIIToUTF16("Google News"));
@@ -793,6 +945,7 @@ TEST_F(TopSitesTest, Migration) {
   hs.AppendMockPage(google1_url, google_title);
   hs.AppendMockPage(news_url, news_title);
   top_sites().SetMockHistoryService(&hs);
+  MessageLoop::current()->RunAllPending();
 
   top_sites().StartMigration();
   EXPECT_TRUE(top_sites().migration_in_progress_);
@@ -837,9 +990,12 @@ TEST_F(TopSitesTest, QueueingRequestsForTopSites) {
 
   EXPECT_EQ(3u, number_of_callbacks());
 
-  ASSERT_EQ(2u, urls().size());
+  ASSERT_EQ(4u, urls().size());
   EXPECT_EQ("http://1.com/", urls()[0].url.spec());
   EXPECT_EQ("http://2.com/", urls()[1].url.spec());
+  EXPECT_EQ(welcome_url(), urls()[2].url);
+  EXPECT_EQ(themes_url(), urls()[3].url);
+
 
   url.url = GURL("http://3.com/");
   url.redirects.push_back(url.url);
@@ -854,13 +1010,17 @@ TEST_F(TopSitesTest, QueueingRequestsForTopSites) {
 
   EXPECT_EQ(4u, number_of_callbacks());
 
-  ASSERT_EQ(3u, urls().size());
+  ASSERT_EQ(5u, urls().size());
   EXPECT_EQ("http://1.com/", urls()[0].url.spec());
   EXPECT_EQ("http://2.com/", urls()[1].url.spec());
   EXPECT_EQ("http://3.com/", urls()[2].url.spec());
+  EXPECT_EQ(welcome_url(), urls()[3].url);
+  EXPECT_EQ(themes_url(), urls()[4].url);
+
 }
 
 TEST_F(TopSitesTest, CancelingRequestsForTopSites) {
+  ChromeThread db_loop(ChromeThread::DB, MessageLoop::current());
   CancelableRequestConsumer c1;
   CancelableRequestConsumer c2;
   top_sites().GetMostVisitedURLs(
@@ -895,11 +1055,13 @@ TEST_F(TopSitesTest, CancelingRequestsForTopSites) {
   pages.push_back(url);
 
   top_sites().OnTopSitesAvailable(0, pages);
+  MessageLoop::current()->RunAllPending();
 
   // 1 request was canceled.
   EXPECT_EQ(2u, number_of_callbacks());
 
-  ASSERT_EQ(2u, urls().size());
+  // 2 extra prepopulated URLs.
+  ASSERT_EQ(4u, urls().size());
   EXPECT_EQ("http://1.com/", urls()[0].url.spec());
   EXPECT_EQ("http://2.com/", urls()[1].url.spec());
 }
@@ -947,4 +1109,232 @@ TEST_F(TopSitesTest, AddTemporaryThumbnail) {
                       thumbnail.getSize()));
 }
 
+TEST_F(TopSitesTest, Blacklisting) {
+  ChromeThread db_loop(ChromeThread::DB, MessageLoop::current());
+  MostVisitedURLList pages;
+  MostVisitedURL url, url1;
+  url.url = GURL("http://bbc.com/");
+  url.redirects.push_back(url.url);
+  pages.push_back(url);
+  url1.url = GURL("http://google.com/");
+  url1.redirects.push_back(url1.url);
+  pages.push_back(url1);
+
+  CancelableRequestConsumer c;
+  top_sites().GetMostVisitedURLs(
+      &c,
+      NewCallback(static_cast<TopSitesTest*>(this),
+                  &TopSitesTest::OnTopSitesAvailable));
+  top_sites().OnTopSitesAvailable(0, pages);
+  MessageLoop::current()->RunAllPending();
+  {
+    Lock& l = lock();
+    AutoLock lock(l);  // IsBlacklisted must be in a lock.
+    EXPECT_FALSE(top_sites().IsBlacklisted(GURL("http://bbc.com/")));
+  }
+
+  EXPECT_EQ(1u, number_of_callbacks());
+
+  ASSERT_EQ(4u, urls().size());
+  EXPECT_EQ("http://bbc.com/", urls()[0].url.spec());
+  EXPECT_EQ("http://google.com/", urls()[1].url.spec());
+  EXPECT_EQ(welcome_url(), urls()[2].url);
+  EXPECT_EQ(themes_url(), urls()[3].url);
+  EXPECT_FALSE(top_sites().HasBlacklistedItems());
+
+  top_sites().AddBlacklistedURL(GURL("http://google.com/"));
+  EXPECT_TRUE(top_sites().HasBlacklistedItems());
+  {
+    Lock& l = lock();
+    AutoLock lock(l);  // IsBlacklisted must be in a lock.
+    EXPECT_TRUE(top_sites().IsBlacklisted(GURL("http://google.com/")));
+    EXPECT_FALSE(top_sites().IsBlacklisted(GURL("http://bbc.com/")));
+    EXPECT_FALSE(top_sites().IsBlacklisted(welcome_url()));
+  }
+
+  top_sites().GetMostVisitedURLs(
+      &c,
+      NewCallback(static_cast<TopSitesTest*>(this),
+                  &TopSitesTest::OnTopSitesAvailable));
+  MessageLoop::current()->RunAllPending();
+  EXPECT_EQ(2u, number_of_callbacks());
+  ASSERT_EQ(3u, urls().size());
+  EXPECT_EQ("http://bbc.com/", urls()[0].url.spec());
+  EXPECT_EQ(welcome_url(), urls()[1].url);
+  EXPECT_EQ(themes_url(), urls()[2].url);
+
+  top_sites().AddBlacklistedURL(welcome_url());
+  EXPECT_TRUE(top_sites().HasBlacklistedItems());
+  top_sites().GetMostVisitedURLs(
+      &c,
+      NewCallback(static_cast<TopSitesTest*>(this),
+                  &TopSitesTest::OnTopSitesAvailable));
+  ASSERT_EQ(2u, urls().size());
+  EXPECT_EQ("http://bbc.com/", urls()[0].url.spec());
+  EXPECT_EQ(themes_url(), urls()[1].url);
+
+  top_sites().RemoveBlacklistedURL(GURL("http://google.com/"));
+  EXPECT_TRUE(top_sites().HasBlacklistedItems());
+  {
+    Lock& l = lock();
+    AutoLock lock(l);  // IsBlacklisted must be in a lock.
+    EXPECT_FALSE(top_sites().IsBlacklisted(GURL("http://google.com/")));
+  }
+
+  top_sites().GetMostVisitedURLs(
+      &c,
+      NewCallback(static_cast<TopSitesTest*>(this),
+                  &TopSitesTest::OnTopSitesAvailable));
+  ASSERT_EQ(3u, urls().size());
+  EXPECT_EQ("http://bbc.com/", urls()[0].url.spec());
+  EXPECT_EQ("http://google.com/", urls()[1].url.spec());
+  EXPECT_EQ(themes_url(), urls()[2].url);
+
+  top_sites().ClearBlacklistedURLs();
+  EXPECT_FALSE(top_sites().HasBlacklistedItems());
+  top_sites().GetMostVisitedURLs(
+      &c,
+      NewCallback(static_cast<TopSitesTest*>(this),
+                  &TopSitesTest::OnTopSitesAvailable));
+  ASSERT_EQ(4u, urls().size());
+  EXPECT_EQ("http://bbc.com/", urls()[0].url.spec());
+  EXPECT_EQ("http://google.com/", urls()[1].url.spec());
+  EXPECT_EQ(welcome_url(), urls()[2].url);
+  EXPECT_EQ(themes_url(), urls()[3].url);
+}
+
+TEST_F(TopSitesTest, PinnedURLs) {
+  ChromeThread db_loop(ChromeThread::DB, MessageLoop::current());
+  MostVisitedURLList pages;
+  MostVisitedURL url, url1;
+  url.url = GURL("http://bbc.com/");
+  url.redirects.push_back(url.url);
+  pages.push_back(url);
+  url1.url = GURL("http://google.com/");
+  url1.redirects.push_back(url1.url);
+  pages.push_back(url1);
+
+  CancelableRequestConsumer c;
+  top_sites().GetMostVisitedURLs(
+      &c,
+      NewCallback(static_cast<TopSitesTest*>(this),
+                  &TopSitesTest::OnTopSitesAvailable));
+  top_sites().OnTopSitesAvailable(0, pages);
+  MessageLoop::current()->RunAllPending();
+  EXPECT_FALSE(top_sites().IsURLPinned(GURL("http://bbc.com/")));
+
+  ASSERT_EQ(4u, urls().size());
+  EXPECT_EQ("http://bbc.com/", urls()[0].url.spec());
+  EXPECT_EQ("http://google.com/", urls()[1].url.spec());
+  EXPECT_EQ(welcome_url(), urls()[2].url);
+  EXPECT_EQ(themes_url(), urls()[3].url);
+
+  top_sites().AddPinnedURL(GURL("http://google.com/"), 3);
+  EXPECT_FALSE(top_sites().IsURLPinned(GURL("http://bbc.com/")));
+  EXPECT_FALSE(top_sites().IsURLPinned(welcome_url()));
+
+  top_sites().GetMostVisitedURLs(
+      &c,
+      NewCallback(static_cast<TopSitesTest*>(this),
+                  &TopSitesTest::OnTopSitesAvailable));
+  EXPECT_EQ(2u, number_of_callbacks());
+  ASSERT_EQ(4u, urls().size());
+  EXPECT_EQ("http://bbc.com/", urls()[0].url.spec());
+  EXPECT_EQ(welcome_url(), urls()[1].url);
+  EXPECT_EQ(themes_url(), urls()[2].url);
+  EXPECT_EQ("http://google.com/", urls()[3].url.spec());
+
+  top_sites().RemovePinnedURL(GURL("http://google.com/"));
+  EXPECT_FALSE(top_sites().IsURLPinned(GURL("http://google.com/")));
+  top_sites().GetMostVisitedURLs(
+      &c,
+      NewCallback(static_cast<TopSitesTest*>(this),
+                  &TopSitesTest::OnTopSitesAvailable));
+
+  ASSERT_EQ(4u, urls().size());
+  EXPECT_EQ("http://bbc.com/", urls()[0].url.spec());
+  EXPECT_EQ("http://google.com/", urls()[1].url.spec());
+  EXPECT_EQ(welcome_url(), urls()[2].url);
+  EXPECT_EQ(themes_url(), urls()[3].url);
+
+  top_sites().AddPinnedURL(GURL("http://bbc.com"), 1);
+  top_sites().AddPinnedURL(themes_url(), 0);
+  top_sites().GetMostVisitedURLs(
+      &c,
+      NewCallback(static_cast<TopSitesTest*>(this),
+                  &TopSitesTest::OnTopSitesAvailable));
+
+  ASSERT_EQ(4u, urls().size());
+  EXPECT_EQ(themes_url(), urls()[0].url);
+  EXPECT_EQ("http://bbc.com/", urls()[1].url.spec());
+  EXPECT_EQ("http://google.com/", urls()[2].url.spec());
+  EXPECT_EQ(welcome_url(), urls()[3].url);
+
+  top_sites().RemovePinnedURL(GURL("http://bbc.com"));
+  top_sites().RemovePinnedURL(themes_url());
+
+  top_sites().AddPinnedURL(welcome_url(), 1);
+  top_sites().AddPinnedURL(GURL("http://bbc.com"), 3);
+
+  top_sites().GetMostVisitedURLs(
+      &c,
+      NewCallback(static_cast<TopSitesTest*>(this),
+                  &TopSitesTest::OnTopSitesAvailable));
+
+  ASSERT_EQ(4u, urls().size());
+  EXPECT_EQ("http://google.com/", urls()[0].url.spec());
+  EXPECT_EQ(welcome_url(), urls()[1].url);
+  EXPECT_EQ(themes_url(), urls()[2].url);
+  EXPECT_EQ("http://bbc.com/", urls()[3].url.spec());
+}
+
+TEST_F(TopSitesTest, BlacklistingAndPinnedURLs) {
+  ChromeThread db_loop(ChromeThread::DB, MessageLoop::current());
+  MostVisitedURLList pages;
+  CancelableRequestConsumer c;
+  top_sites().GetMostVisitedURLs(
+      &c,
+      NewCallback(static_cast<TopSitesTest*>(this),
+                  &TopSitesTest::OnTopSitesAvailable));
+  top_sites().OnTopSitesAvailable(0, pages);
+  MessageLoop::current()->RunAllPending();
+
+  ASSERT_EQ(2u, urls().size());
+  EXPECT_EQ(welcome_url(), urls()[0].url);
+  EXPECT_EQ(themes_url(), urls()[1].url);
+
+  top_sites().AddPinnedURL(themes_url(), 1);
+  top_sites().AddBlacklistedURL(welcome_url());
+
+  top_sites().GetMostVisitedURLs(
+      &c,
+      NewCallback(static_cast<TopSitesTest*>(this),
+                  &TopSitesTest::OnTopSitesAvailable));
+
+  ASSERT_EQ(2u, urls().size());
+  EXPECT_EQ(GURL(), urls()[0].url);
+  EXPECT_EQ(themes_url(), urls()[1].url);
+
+}
+
+TEST_F(TopSitesTest, AddPrepopulatedPages) {
+  MostVisitedURLList pages;
+  top_sites().AddPrepopulatedPages(&pages);
+  ASSERT_EQ(2u, pages.size());
+  EXPECT_EQ(welcome_url(), pages[0].url);
+  EXPECT_EQ(themes_url(), pages[1].url);
+
+  pages.clear();
+
+  MostVisitedURL url = {themes_url()};
+  pages.push_back(url);
+
+  top_sites().AddPrepopulatedPages(&pages);
+
+  // Themes URL is already in pages; should not be added twice.
+  ASSERT_EQ(2u, pages.size());
+  EXPECT_EQ(themes_url(), pages[0].url);
+  EXPECT_EQ(welcome_url(), pages[1].url);
+}
+
 }  // namespace history
diff --git a/chrome/browser/history/url_database.cc b/chrome/browser/history/url_database.cc
index 07f8881..b63d24a 100644
--- a/chrome/browser/history/url_database.cc
+++ b/chrome/browser/history/url_database.cc
@@ -10,7 +10,6 @@
 #include <vector>
 
 #include "app/l10n_util.h"
-#include "app/sql/connection.h"
 #include "app/sql/statement.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/common/url_constants.h"
@@ -346,7 +345,7 @@ bool URLDatabase::DropKeywordSearchTermsTable() {
 }
 
 bool URLDatabase::SetKeywordSearchTermsForURL(URLID url_id,
-                                              TemplateURL::IDType keyword_id,
+                                              TemplateURLID keyword_id,
                                               const string16& term) {
   DCHECK(url_id && keyword_id && !term.empty());
 
@@ -374,7 +373,7 @@ bool URLDatabase::SetKeywordSearchTermsForURL(URLID url_id,
 }
 
 void URLDatabase::DeleteAllSearchTermsForKeyword(
-    TemplateURL::IDType keyword_id) {
+    TemplateURLID keyword_id) {
   DCHECK(keyword_id);
   sql::Statement statement(GetDB().GetCachedStatement(SQL_FROM_HERE,
       "DELETE FROM keyword_search_terms WHERE keyword_id=?"));
@@ -386,7 +385,7 @@ void URLDatabase::DeleteAllSearchTermsForKeyword(
 }
 
 void URLDatabase::GetMostRecentKeywordSearchTerms(
-    TemplateURL::IDType keyword_id,
+    TemplateURLID keyword_id,
     const string16& prefix,
     int max_count,
     std::vector<KeywordSearchTermVisit>* matches) {
diff --git a/chrome/browser/history/url_database.h b/chrome/browser/history/url_database.h
index 84c8dde..36bfebb 100644
--- a/chrome/browser/history/url_database.h
+++ b/chrome/browser/history/url_database.h
@@ -4,11 +4,12 @@
 
 #ifndef CHROME_BROWSER_HISTORY_URL_DATABASE_H_
 #define CHROME_BROWSER_HISTORY_URL_DATABASE_H_
+#pragma once
 
 #include "app/sql/statement.h"
 #include "base/basictypes.h"
 #include "chrome/browser/history/history_types.h"
-#include "chrome/browser/search_engines/template_url.h"
+#include "chrome/browser/search_engines/template_url_id.h"
 
 class GURL;
 
@@ -159,17 +160,17 @@ class URLDatabase {
 
   // Sets the search terms for the specified url/keyword pair.
   bool SetKeywordSearchTermsForURL(URLID url_id,
-                                   TemplateURL::IDType keyword_id,
+                                   TemplateURLID keyword_id,
                                    const string16& term);
 
   // Deletes all search terms for the specified keyword that have been added by
   // way of SetKeywordSearchTermsForURL.
-  void DeleteAllSearchTermsForKeyword(TemplateURL::IDType keyword_id);
+  void DeleteAllSearchTermsForKeyword(TemplateURLID keyword_id);
 
   // Returns up to max_count of the most recent search terms for the specified
   // keyword.
   void GetMostRecentKeywordSearchTerms(
-      TemplateURL::IDType keyword_id,
+      TemplateURLID keyword_id,
       const string16& prefix,
       int max_count,
       std::vector<KeywordSearchTermVisit>* matches);
diff --git a/chrome/browser/history/url_database_unittest.cc b/chrome/browser/history/url_database_unittest.cc
index 32ded0c..f567844 100644
--- a/chrome/browser/history/url_database_unittest.cc
+++ b/chrome/browser/history/url_database_unittest.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -67,9 +67,9 @@ class URLDatabaseTest : public testing::Test,
   sql::Connection db_;
 };
 
-// Test add and query for the URL table in the HistoryDatabase
+// Test add and query for the URL table in the HistoryDatabase.
 TEST_F(URLDatabaseTest, AddURL) {
-  // first, add two URLs
+  // First, add two URLs.
   const GURL url1("http://www.google.com/");
   URLRow url_info1(url1);
   url_info1.set_title(UTF8ToUTF16("Google"));
@@ -88,7 +88,7 @@ TEST_F(URLDatabaseTest, AddURL) {
   url_info2.set_hidden(true);
   EXPECT_TRUE(AddURL(url_info2));
 
-  // query both of them
+  // Query both of them.
   URLRow info;
   EXPECT_TRUE(GetRowForURL(url1, &info));
   EXPECT_TRUE(IsURLRowEqual(url_info1, info));
@@ -96,7 +96,7 @@ TEST_F(URLDatabaseTest, AddURL) {
   EXPECT_TRUE(id2);
   EXPECT_TRUE(IsURLRowEqual(url_info2, info));
 
-  // update the second
+  // Update the second.
   url_info2.set_title(UTF8ToUTF16("Google Mail Too"));
   url_info2.set_visit_count(4);
   url_info2.set_typed_count(1);
@@ -104,19 +104,19 @@ TEST_F(URLDatabaseTest, AddURL) {
   url_info2.set_hidden(false);
   EXPECT_TRUE(UpdateURLRow(id2, url_info2));
 
-  // make sure it got updated
+  // Make sure it got updated.
   URLRow info2;
   EXPECT_TRUE(GetRowForURL(url2, &info2));
   EXPECT_TRUE(IsURLRowEqual(url_info2, info2));
 
-  // query a nonexistant URL
+  // Query a nonexistent URL.
   EXPECT_EQ(0, GetRowForURL(GURL("http://news.google.com/"), &info));
 
-  // Delete all urls in the domain
+  // Delete all urls in the domain.
   // TODO(acw): test the new url based delete domain
   // EXPECT_TRUE(db.DeleteDomain(kDomainID));
 
-  // Make sure the urls have been properly removed
+  // Make sure the urls have been properly removed.
   // TODO(acw): commented out because remove no longer works.
   // EXPECT_TRUE(db.GetURLInfo(url1, NULL) == NULL);
   // EXPECT_TRUE(db.GetURLInfo(url2, NULL) == NULL);
diff --git a/chrome/browser/history/visit_database.cc b/chrome/browser/history/visit_database.cc
index 80fa8c8..d0156c2 100644
--- a/chrome/browser/history/visit_database.cc
+++ b/chrome/browser/history/visit_database.cc
@@ -9,9 +9,9 @@
 #include <map>
 #include <set>
 
-#include "app/sql/connection.h"
 #include "app/sql/statement.h"
 #include "base/logging.h"
+#include "base/string_number_conversions.h"
 #include "chrome/browser/history/url_database.h"
 #include "chrome/common/page_transition_types.h"
 #include "chrome/common/url_constants.h"
@@ -51,6 +51,17 @@ bool VisitDatabase::InitVisitTable() {
       return false;
   }
 
+  // Visit source table contains the source information for all the visits. To
+  // save space, we do not record those user browsed visits which would be the
+  // majority in this table. Only other sources are recorded.
+  // Due to the tight relationship between visit_source and visits table, they
+  // should be created and dropped at the same time.
+  if (!GetDB().DoesTableExist("visit_source")) {
+    if (!GetDB().Execute("CREATE TABLE visit_source("
+                         "id INTEGER PRIMARY KEY,source INTEGER NOT NULL)"))
+        return false;
+  }
+
   // Index over url so we can quickly find visits for a page. This will just
   // fail if it already exists and we'll ignore it.
   GetDB().Execute("CREATE INDEX visits_url_index ON visits (url)");
@@ -68,6 +79,7 @@ bool VisitDatabase::InitVisitTable() {
 }
 
 bool VisitDatabase::DropVisitTable() {
+  GetDB().Execute("DROP TABLE visit_source");
   // This will also drop the indices over the table.
   return GetDB().Execute("DROP TABLE visits");
 }
@@ -94,7 +106,7 @@ void VisitDatabase::FillVisitVector(sql::Statement& statement,
   }
 }
 
-VisitID VisitDatabase::AddVisit(VisitRow* visit) {
+VisitID VisitDatabase::AddVisit(VisitRow* visit, VisitSource source) {
   sql::Statement statement(GetDB().GetCachedStatement(SQL_FROM_HERE,
       "INSERT INTO visits "
       "(url, visit_time, from_visit, transition, segment_id, is_indexed) "
@@ -112,6 +124,20 @@ VisitID VisitDatabase::AddVisit(VisitRow* visit) {
     return 0;
 
   visit->visit_id = GetDB().GetLastInsertRowId();
+
+  if (source != SOURCE_BROWSED) {
+    // Record the source of this visit when it is not browsed.
+    sql::Statement statement1(GetDB().GetCachedStatement(SQL_FROM_HERE,
+        "INSERT INTO visit_source (id, source) VALUES (?,?)"));
+    if (!statement1.is_valid())
+      return 0;
+
+    statement1.BindInt64(0, visit->visit_id);
+    statement1.BindInt64(1, source);
+    if (!statement1.Run())
+      return 0;
+  }
+
   return visit->visit_id;
 }
 
@@ -133,6 +159,16 @@ void VisitDatabase::DeleteVisit(const VisitRow& visit) {
     return;
   del.BindInt64(0, visit.visit_id);
   del.Run();
+
+  // Try to delete the entry in visit_source table as well.
+  // If the visit was browsed, there is no corresponding entry in visit_source
+  // table, and nothing will be deleted.
+  del.Assign(GetDB().GetCachedStatement(SQL_FROM_HERE,
+             "DELETE FROM visit_source WHERE id=?"));
+  if (!del.is_valid())
+    return;
+  del.BindInt64(0, visit.visit_id);
+  del.Run();
 }
 
 bool VisitDatabase::GetRowForVisit(VisitID visit_id, VisitRow* out_visit) {
@@ -437,4 +473,42 @@ bool VisitDatabase::GetStartDate(base::Time* first_visit) {
   return true;
 }
 
+void VisitDatabase::GetVisitsSource(const VisitVector& visits,
+                                    VisitSourceMap* sources) {
+  DCHECK(sources);
+  sources->clear();
+
+  // We query the source in batch. Here defines the batch size.
+  const size_t batch_size = 500;
+  size_t visits_size = visits.size();
+
+  size_t start_index = 0, end_index = 0;
+  while (end_index < visits_size) {
+    start_index = end_index;
+    end_index = end_index + batch_size < visits_size ? end_index + batch_size
+                                                     : visits_size;
+
+    // Compose the sql statement with a list of ids.
+    std::string sql = "SELECT id,source FROM visit_source ";
+    sql.append("WHERE id IN (");
+    // Append all the ids in the statement.
+    for (size_t j = start_index; j < end_index; j++) {
+      if (j != start_index)
+        sql.push_back(',');
+      sql.append(base::Int64ToString(visits[j].visit_id));
+    }
+    sql.append(") ORDER BY id");
+    sql::Statement statement(GetDB().GetUniqueStatement(sql.c_str()));
+    if (!statement)
+      return;
+
+    // Get the source entries out of the query result.
+    while (statement.Step()) {
+      std::pair<VisitID, VisitSource> source_entry(statement.ColumnInt64(0),
+          static_cast<VisitSource>(statement.ColumnInt(1)));
+      sources->insert(source_entry);
+    }
+  }
+}
+
 }  // namespace history
diff --git a/chrome/browser/history/visit_database.h b/chrome/browser/history/visit_database.h
index a6dbf3c..0e97cac 100644
--- a/chrome/browser/history/visit_database.h
+++ b/chrome/browser/history/visit_database.h
@@ -4,6 +4,7 @@
 
 #ifndef CHROME_BROWSER_HISTORY_VISIT_DATABASE_H_
 #define CHROME_BROWSER_HISTORY_VISIT_DATABASE_H_
+#pragma once
 
 #include "chrome/browser/history/history_types.h"
 
@@ -33,8 +34,9 @@ class VisitDatabase {
 
   // Adds a line to the visit database with the given information, returning
   // the added row ID on success, 0 on failure. The given visit is updated with
-  // the new row ID on success.
-  VisitID AddVisit(VisitRow* visit);
+  // the new row ID on success. In addition, adds its source into visit_source
+  // table.
+  VisitID AddVisit(VisitRow* visit, VisitSource source);
 
   // Deletes the given visit from the database. If a visit with the given ID
   // doesn't exist, it will not do anything.
@@ -143,6 +145,10 @@ class VisitDatabase {
   // Get the time of the first item in our database.
   bool GetStartDate(base::Time* first_visit);
 
+  // Get the source information about the given visits.
+  void GetVisitsSource(const VisitVector& visits,
+                       VisitSourceMap* sources);
+
  protected:
   // Returns the database for the functions in this interface.
   virtual sql::Connection& GetDB() = 0;
diff --git a/chrome/browser/history/visit_database_unittest.cc b/chrome/browser/history/visit_database_unittest.cc
index ebc2e1b..28a0e15 100644
--- a/chrome/browser/history/visit_database_unittest.cc
+++ b/chrome/browser/history/visit_database_unittest.cc
@@ -73,19 +73,19 @@ class VisitDatabaseTest : public PlatformTest,
 TEST_F(VisitDatabaseTest, Add) {
   // Add one visit.
   VisitRow visit_info1(1, Time::Now(), 0, PageTransition::LINK, 0);
-  EXPECT_TRUE(AddVisit(&visit_info1));
+  EXPECT_TRUE(AddVisit(&visit_info1, SOURCE_BROWSED));
 
   // Add second visit for the same page.
   VisitRow visit_info2(visit_info1.url_id,
       visit_info1.visit_time + TimeDelta::FromSeconds(1), 1,
       PageTransition::TYPED, 0);
-  EXPECT_TRUE(AddVisit(&visit_info2));
+  EXPECT_TRUE(AddVisit(&visit_info2, SOURCE_BROWSED));
 
   // Add third visit for a different page.
   VisitRow visit_info3(2,
       visit_info1.visit_time + TimeDelta::FromSeconds(2), 0,
       PageTransition::LINK, 0);
-  EXPECT_TRUE(AddVisit(&visit_info3));
+  EXPECT_TRUE(AddVisit(&visit_info3, SOURCE_BROWSED));
 
   // Query the first two.
   std::vector<VisitRow> matches;
@@ -104,17 +104,17 @@ TEST_F(VisitDatabaseTest, Delete) {
   static const int kTime1 = 1000;
   VisitRow visit_info1(1, Time::FromInternalValue(kTime1), 0,
                        PageTransition::LINK, 0);
-  EXPECT_TRUE(AddVisit(&visit_info1));
+  EXPECT_TRUE(AddVisit(&visit_info1, SOURCE_BROWSED));
 
   static const int kTime2 = kTime1 + 1;
   VisitRow visit_info2(1, Time::FromInternalValue(kTime2),
                        visit_info1.visit_id, PageTransition::LINK, 0);
-  EXPECT_TRUE(AddVisit(&visit_info2));
+  EXPECT_TRUE(AddVisit(&visit_info2, SOURCE_BROWSED));
 
   static const int kTime3 = kTime2 + 1;
   VisitRow visit_info3(1, Time::FromInternalValue(kTime3),
                        visit_info2.visit_id, PageTransition::LINK, 0);
-  EXPECT_TRUE(AddVisit(&visit_info3));
+  EXPECT_TRUE(AddVisit(&visit_info3, SOURCE_BROWSED));
 
   // First make sure all the visits are there.
   std::vector<VisitRow> matches;
@@ -140,7 +140,7 @@ TEST_F(VisitDatabaseTest, Delete) {
 TEST_F(VisitDatabaseTest, Update) {
   // Make something in the database.
   VisitRow original(1, Time::Now(), 23, 22, 19);
-  AddVisit(&original);
+  AddVisit(&original, SOURCE_BROWSED);
 
   // Mutate that row.
   VisitRow modification(original);
@@ -167,7 +167,7 @@ TEST_F(VisitDatabaseTest, GetVisibleVisitsInRange) {
                                         PageTransition::CHAIN_END),
       0);
   visit_info1.visit_id = 1;
-  EXPECT_TRUE(AddVisit(&visit_info1));
+  EXPECT_TRUE(AddVisit(&visit_info1, SOURCE_BROWSED));
 
   // Add second visit for the same page.
   VisitRow visit_info2(visit_info1.url_id,
@@ -177,7 +177,7 @@ TEST_F(VisitDatabaseTest, GetVisibleVisitsInRange) {
                                         PageTransition::CHAIN_END),
       0);
   visit_info2.visit_id = 2;
-  EXPECT_TRUE(AddVisit(&visit_info2));
+  EXPECT_TRUE(AddVisit(&visit_info2, SOURCE_BROWSED));
 
   // Add third visit for a different page.
   VisitRow visit_info3(2,
@@ -186,7 +186,7 @@ TEST_F(VisitDatabaseTest, GetVisibleVisitsInRange) {
                                         PageTransition::CHAIN_START),
       0);
   visit_info3.visit_id = 3;
-  EXPECT_TRUE(AddVisit(&visit_info3));
+  EXPECT_TRUE(AddVisit(&visit_info3, SOURCE_BROWSED));
 
   // Add a redirect visit from the last page.
   VisitRow visit_info4(3,
@@ -195,7 +195,7 @@ TEST_F(VisitDatabaseTest, GetVisibleVisitsInRange) {
                                         PageTransition::CHAIN_END),
       0);
   visit_info4.visit_id = 4;
-  EXPECT_TRUE(AddVisit(&visit_info4));
+  EXPECT_TRUE(AddVisit(&visit_info4, SOURCE_BROWSED));
 
   // Add a subframe visit.
   VisitRow visit_info5(4,
@@ -205,7 +205,7 @@ TEST_F(VisitDatabaseTest, GetVisibleVisitsInRange) {
                                         PageTransition::CHAIN_END),
       0);
   visit_info5.visit_id = 5;
-  EXPECT_TRUE(AddVisit(&visit_info5));
+  EXPECT_TRUE(AddVisit(&visit_info5, SOURCE_BROWSED));
 
   // Query the visits for all time, we should not get the first (duplicate of
   // the second) or the redirect or subframe visits.
@@ -227,4 +227,37 @@ TEST_F(VisitDatabaseTest, GetVisibleVisitsInRange) {
   ASSERT_EQ(static_cast<size_t>(1), results.size());
   EXPECT_TRUE(IsVisitInfoEqual(results[0], visit_info4));
 }
+
+TEST_F(VisitDatabaseTest, VisitSource) {
+  // Add visits.
+  VisitRow visit_info1(111, Time::Now(), 0, PageTransition::LINK, 0);
+  ASSERT_TRUE(AddVisit(&visit_info1, SOURCE_BROWSED));
+
+  VisitRow visit_info2(112, Time::Now(), 1, PageTransition::TYPED, 0);
+  ASSERT_TRUE(AddVisit(&visit_info2, SOURCE_SYNCED));
+
+  VisitRow visit_info3(113, Time::Now(), 0, PageTransition::TYPED, 0);
+  ASSERT_TRUE(AddVisit(&visit_info3, SOURCE_EXTENSION));
+
+  // Query each visit.
+  std::vector<VisitRow> matches;
+  ASSERT_TRUE(GetVisitsForURL(111, &matches));
+  ASSERT_EQ(1U, matches.size());
+  VisitSourceMap sources;
+  GetVisitsSource(matches, &sources);
+  EXPECT_EQ(0U, sources.size());
+
+  ASSERT_TRUE(GetVisitsForURL(112, &matches));
+  ASSERT_EQ(1U, matches.size());
+  GetVisitsSource(matches, &sources);
+  ASSERT_EQ(1U, sources.size());
+  EXPECT_EQ(SOURCE_SYNCED, sources[matches[0].visit_id]);
+
+  ASSERT_TRUE(GetVisitsForURL(113, &matches));
+  ASSERT_EQ(1U, matches.size());
+  GetVisitsSource(matches, &sources);
+  ASSERT_EQ(1U, sources.size());
+  EXPECT_EQ(SOURCE_EXTENSION, sources[matches[0].visit_id]);
+}
+
 }  // namespace history
diff --git a/chrome/browser/history/visit_tracker.h b/chrome/browser/history/visit_tracker.h
index 43de7a0..281c136 100644
--- a/chrome/browser/history/visit_tracker.h
+++ b/chrome/browser/history/visit_tracker.h
@@ -4,6 +4,7 @@
 
 #ifndef CHROME_BROWSER_HISTORY_VISIT_TRACKER_H__
 #define CHROME_BROWSER_HISTORY_VISIT_TRACKER_H__
+#pragma once
 
 #include <map>
 #include <vector>
diff --git a/chrome/browser/history/visitsegment_database.cc b/chrome/browser/history/visitsegment_database.cc
index f94d713..f4c4f9f 100644
--- a/chrome/browser/history/visitsegment_database.cc
+++ b/chrome/browser/history/visitsegment_database.cc
@@ -10,7 +10,6 @@
 #include <string>
 #include <vector>
 
-#include "app/sql/connection.h"
 #include "app/sql/statement.h"
 #include "base/logging.h"
 #include "base/stl_util-inl.h"
diff --git a/chrome/browser/history/visitsegment_database.h b/chrome/browser/history/visitsegment_database.h
index 16f0417..7c25ef7 100644
--- a/chrome/browser/history/visitsegment_database.h
+++ b/chrome/browser/history/visitsegment_database.h
@@ -4,6 +4,7 @@
 
 #ifndef CHROME_BROWSER_HISTORY_VISITSEGMENT_DATABASE_H_
 #define CHROME_BROWSER_HISTORY_VISITSEGMENT_DATABASE_H_
+#pragma once
 
 #include "base/basictypes.h"
 #include "chrome/browser/history/history_types.h"