Adding an SQLite database for TopSites.

BUG=None
TEST=TopSitesTest

Review URL: http://codereview.chromium.org/2249004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@48639 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 495 insertions, 9 deletions

diff --git a/chrome/browser/history/top_sites.cc b/chrome/browser/history/top_sites.cc
index ab610a0..d8ea651 100644
--- a/chrome/browser/history/top_sites.cc
+++ b/chrome/browser/history/top_sites.cc
@@ -82,14 +82,15 @@ bool TopSites::SetPageThumbnail(const GURL& url,
   Images& image = top_images_[most_visited.url];
 
   // When comparing the thumbnail scores, we need to take into account the
-  // redirect hops, which are not generated when the thumbnail is becuase the
+  // redirect hops, which are not generated when the thumbnail is because the
   // redirects weren't known. We fill that in here since we know the redirects.
   ThumbnailScore new_score_with_redirects(score);
   new_score_with_redirects.redirect_hops_from_dest =
       GetRedirectDistanceForURL(most_visited, url);
 
   if (!ShouldReplaceThumbnailWith(image.thumbnail_score,
-                                  new_score_with_redirects))
+                                  new_score_with_redirects) &&
+      image.thumbnail.get())
     return false;  // The one we already have is better.
 
   // Take ownership of the thumbnail data.
diff --git a/chrome/browser/history/top_sites.h b/chrome/browser/history/top_sites.h
index 0b9b1e4..4f6f854 100644
--- a/chrome/browser/history/top_sites.h
+++ b/chrome/browser/history/top_sites.h
@@ -86,7 +86,8 @@ class TopSites : public base::RefCountedThreadSafe<TopSites> {
   friend class base::RefCountedThreadSafe<TopSites>;
   friend class TopSitesTest;
   friend class TopSitesTest_GetMostVisited_Test;
-  friend class TopSitesTest_ReadDatabase_Test;
+  friend class TopSitesTest_RealDatabase_Test;
+  friend class TopSitesTest_MockDatabase_Test;
 
   ~TopSites();
 
diff --git a/chrome/browser/history/top_sites_database.cc b/chrome/browser/history/top_sites_database.cc
new file mode 100644
index 0000000..5b13d61
--- /dev/null
+++ b/chrome/browser/history/top_sites_database.cc
@@ -0,0 +1,235 @@
+// Copyright (c) 2009 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/sql/transaction.h"
+#include "base/string_util.h"
+#include "chrome/browser/diagnostics/sqlite_diagnostics.h"
+#include "chrome/browser/history/top_sites.h"
+#include "chrome/browser/history/top_sites_database.h"
+
+namespace history {
+
+TopSitesDatabaseImpl::TopSitesDatabaseImpl() {
+}
+
+bool TopSitesDatabaseImpl::Init(const FilePath& db_name) {
+  // Settings copied from ThumbnailDatabase.
+  db_.set_error_delegate(GetErrorHandlerForThumbnailDb());
+  db_.set_page_size(4096);
+  db_.set_cache_size(64);
+
+  if (!db_.Open(db_name)) {
+    LOG(WARNING) << db_.GetErrorMessage();
+    return sql::INIT_FAILURE;
+  }
+
+  return InitThumbnailTable();
+}
+
+bool TopSitesDatabaseImpl::InitThumbnailTable() {
+  if (!db_.DoesTableExist("thumbnails")) {
+    if (!db_.Execute("CREATE TABLE thumbnails ("
+                     "url LONGVARCHAR PRIMARY KEY,"
+                     "url_rank INTEGER ,"
+                     "title LONGVARCHAR,"
+                     "thumbnail BLOB,"
+                     "redirects LONGVARCHAR)")) {
+      LOG(WARNING) << db_.GetErrorMessage();
+      return false;
+    }
+  }
+  return true;
+}
+
+MostVisitedURLList TopSitesDatabaseImpl::GetTopURLs() {
+  MostVisitedURLList result;
+  sql::Statement select_statement(db_.GetCachedStatement(
+      SQL_FROM_HERE,
+      "SELECT url, url_rank, title, redirects "
+      "FROM thumbnails ORDER BY url_rank"));
+
+  if (!select_statement) {
+    LOG(WARNING) << db_.GetErrorMessage();
+    return result;
+  }
+
+  int row_count = 0;
+  int max_rank = -1;  // -1 is for the case of empty DB.
+  while (select_statement.Step()) {
+    // Results are sorted by url_rank.
+    MostVisitedURL url;
+    GURL gurl(select_statement.ColumnString(0));
+    url.url = gurl;
+    url.title = select_statement.ColumnString16(2);
+    std::string redirects = select_statement.ColumnString(3);
+    SetRedirects(redirects, &url);
+    result.push_back(url);
+  }
+  DCHECK(select_statement.Succeeded());
+  DCHECK_EQ(max_rank + 1, row_count);
+
+  return result;
+}
+
+// static
+std::string TopSitesDatabaseImpl::GetRedirects(const MostVisitedURL& url) {
+  std::vector<std::string> redirects;
+  for (size_t i = 0; i < url.redirects.size(); i++)
+    redirects.push_back(url.redirects[i].spec());
+  return JoinString(redirects, ' ');
+}
+
+// static
+void TopSitesDatabaseImpl::SetRedirects(const std::string& redirects,
+                                        MostVisitedURL* url) {
+  std::vector<std::string> redirects_vector;
+  SplitStringAlongWhitespace(redirects, &redirects_vector);
+  for (size_t i = 0; i < redirects_vector.size(); i++)
+    url->redirects.push_back(GURL(redirects_vector[i]));
+}
+
+
+void TopSitesDatabaseImpl::SetPageThumbnail(const MostVisitedURL& url,
+                                            int new_rank,
+                                            const TopSites::Images& thumbnail) {
+  sql::Transaction transaction(&db_);
+  transaction.Begin();
+
+  int prev_rank = GetURLRank(url);
+
+  sql::Statement statement(db_.GetCachedStatement(
+      SQL_FROM_HERE,
+      "INSERT OR REPLACE INTO thumbnails "
+      "(url, url_rank, title, thumbnail, redirects) "
+      "VALUES (?, ?, ?, ?, ?)"));  // TODO(Nik): add the rest of the schema.
+  if (!statement)
+    return;
+
+  statement.BindString(0, url.url.spec());
+  statement.BindInt(1, -1);  // Temporary value
+  statement.BindString16(2, url.title);
+  if (thumbnail.thumbnail.get()) {
+    statement.BindBlob(3, &thumbnail.thumbnail->data.front(),
+                       static_cast<int>(thumbnail.thumbnail->data.size()));
+  }
+  statement.BindString(4, GetRedirects(url));
+
+  if (!statement.Run())
+    NOTREACHED() << db_.GetErrorMessage();
+
+  // Shift the ranks.
+  if (prev_rank == -1) {
+    // Shift up
+    sql::Statement shift_statement(db_.GetCachedStatement(
+        SQL_FROM_HERE,
+        "UPDATE thumbnails "
+        "SET url_rank = url_rank + 1 WHERE url_rank >= ?"));
+    shift_statement.BindInt(0, new_rank);
+    if (shift_statement)
+      shift_statement.Run();
+  } else if (prev_rank > new_rank) {
+    // Shift up
+    sql::Statement shift_statement(db_.GetCachedStatement(
+        SQL_FROM_HERE,
+        "UPDATE thumbnails "
+        "SET url_rank = url_rank + 1 "
+        "WHERE url_rank >= ? AND url_rank < ?"));
+    shift_statement.BindInt(0, new_rank);
+    shift_statement.BindInt(1, prev_rank);
+    if (shift_statement)
+      shift_statement.Run();
+  } else if (prev_rank < new_rank) {
+    // Shift down
+    sql::Statement shift_statement(db_.GetCachedStatement(
+        SQL_FROM_HERE,
+        "UPDATE thumbnails "
+        "SET url_rank = url_rank - 1 "
+        "WHERE url_rank > ? AND url_rank <= ?"));
+    shift_statement.BindInt(0, prev_rank);
+    shift_statement.BindInt(1, new_rank);
+    if (shift_statement)
+      shift_statement.Run();
+  }
+
+  // Set the real rank.
+  sql::Statement set_statement(db_.GetCachedStatement(
+      SQL_FROM_HERE,
+      "UPDATE thumbnails "
+      "SET url_rank = ? "
+      "WHERE url_rank == -1"));
+  set_statement.BindInt(0, new_rank);
+  if (set_statement)
+    set_statement.Run();
+  transaction.Commit();
+}
+
+bool TopSitesDatabaseImpl::GetPageThumbnail(const MostVisitedURL& url,
+                                            TopSites::Images* thumbnail) {
+  sql::Statement select_statement(db_.GetCachedStatement(
+      SQL_FROM_HERE,
+      "SELECT thumbnail "
+      "FROM thumbnails WHERE url=?"));
+
+  if (!select_statement) {
+    LOG(WARNING) << db_.GetErrorMessage();
+    return false;
+  }
+
+  select_statement.BindString(0, url.url.spec());
+  if (!select_statement.Step())
+    return false;
+
+  std::vector<unsigned char> data;
+  select_statement.ColumnBlobAsVector(0, &data);
+  thumbnail->thumbnail = RefCountedBytes::TakeVector(&data);
+  return true;
+}
+
+int TopSitesDatabaseImpl::GetURLRank(const MostVisitedURL& url) {
+  int result = -1;
+  sql::Statement select_statement(db_.GetCachedStatement(
+      SQL_FROM_HERE,
+      "SELECT url_rank "
+      "FROM thumbnails WHERE url=?"));
+  if (!select_statement) {
+    LOG(WARNING) << db_.GetErrorMessage();
+    return result;
+  }
+
+  select_statement.BindString(0, url.url.spec());
+  if (select_statement.Step())
+    result = select_statement.ColumnInt(0);
+
+  return result;
+}
+
+// Remove the record for this URL. Returns true iff removed successfully.
+bool TopSitesDatabaseImpl::RemoveURL(const MostVisitedURL& url) {
+  int old_rank = GetURLRank(url);
+  sql::Transaction transaction(&db_);
+  transaction.Begin();
+  // Decrement all following ranks.
+  sql::Statement shift_statement(db_.GetCachedStatement(
+      SQL_FROM_HERE,
+      "UPDATE thumbnails "
+      "SET url_rank = url_rank - 1 "
+      "WHERE url_rank > ?"));
+  if (!shift_statement)
+    return false;
+  shift_statement.BindInt(0, old_rank);
+  shift_statement.Run();
+
+  sql::Statement delete_statement(
+      db_.GetCachedStatement(SQL_FROM_HERE,
+                             "DELETE FROM thumbnails WHERE url = ?"));
+  if (!delete_statement)
+    return false;
+  delete_statement.BindString(0, url.url.spec());
+  delete_statement.Run();
+
+  return transaction.Commit();
+}
+
+}  // namespace history
+
diff --git a/chrome/browser/history/top_sites_database.h b/chrome/browser/history/top_sites_database.h
index 50da75d..2a664a6 100644
--- a/chrome/browser/history/top_sites_database.h
+++ b/chrome/browser/history/top_sites_database.h
@@ -5,6 +5,7 @@
 #ifndef CHROME_BROWSER_HISTORY_TOP_SITES_DATABASE_H_
 #define CHROME_BROWSER_HISTORY_TOP_SITES_DATABASE_H_
 
+#include <string>
 #include <vector>
 
 #include "app/sql/connection.h"
@@ -17,6 +18,7 @@
 class FilePath;
 class RefCountedMemory;
 class SkBitmap;
+class TopSites;
 
 namespace base {
 class Time;
@@ -39,17 +41,68 @@ class TopSitesDatabase {
   // thumbnail.
   virtual void SetPageThumbnail(const MostVisitedURL& url,
                                 int url_rank,
-                                const TopSites::Images thumbnail) = 0;
+                                const TopSites::Images& thumbnail) = 0;
 
   // Get a thumbnail for a given page. Returns true iff we have the thumbnail.
   virtual bool GetPageThumbnail(const MostVisitedURL& url,
-                                TopSites::Images* thumbnail) const = 0;
+                                TopSites::Images* thumbnail) = 0;
 
   // Remove the record for this URL. Returns true iff removed successfully.
   virtual bool RemoveURL(const MostVisitedURL& url) = 0;
 };
 
+class TopSitesDatabaseImpl: public TopSitesDatabase {
+ public:
+  TopSitesDatabaseImpl();
+  ~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.
+  bool Init(const FilePath& db_name);
+
+  // Thumbnails ----------------------------------------------------------------
+
+  // Returns a list of all URLs currently in the table.
+  virtual MostVisitedURLList GetTopURLs();
+
+  // Set a thumbnail for a URL. |url_rank| is the position of the URL
+  // in the list of TopURLs, zero-based.
+  // If the URL is not in the table, add it. If it is, replace its
+  // thumbnail and rank. Shift the ranks of other URLs if necessary.
+  virtual void SetPageThumbnail(const MostVisitedURL& url,
+                                int new_rank,
+                                const TopSites::Images& thumbnail);
+
+  // Get a thumbnail for a given page. Returns true iff we have the thumbnail.
+  virtual bool GetPageThumbnail(const MostVisitedURL& url,
+                                TopSites::Images* thumbnail);
+
+  // Remove the record for this URL. Returns true iff removed successfully.
+  virtual bool RemoveURL(const MostVisitedURL& url);
+
+ private:
+  // Creates the thumbnail table, returning true if the table already exists
+  // or was successfully created.
+  bool InitThumbnailTable();
+
+  // Returns the URL's current rank or -1 if it is not present.
+  int GetURLRank(const MostVisitedURL& url);
+
+  // Gets the URL at |rank|. Returns true if the URL is there.
+  bool GetURLAtRank(int rank, MostVisitedURL* url);
+
+  // Sets the rank of a URL. The URL must be present in the DB.
+  void SetURLRank(const MostVisitedURL& url, int rank);
+
+  // Encodes redirects into a string.
+  static std::string GetRedirects(const MostVisitedURL& url);
+
+  // Decodes redirects from a string and sets them for the url.
+  static void SetRedirects(const std::string& redirects, MostVisitedURL* url);
+
+  sql::Connection db_;
+};
+
 }  // namespace history
 
 #endif  // CHROME_BROWSER_HISTORY_TOP_SITES_DATABASE_H_
-
diff --git a/chrome/browser/history/top_sites_unittest.cc b/chrome/browser/history/top_sites_unittest.cc
index fbc1aeb..7463075 100644
--- a/chrome/browser/history/top_sites_unittest.cc
+++ b/chrome/browser/history/top_sites_unittest.cc
@@ -2,10 +2,13 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "base/scoped_temp_dir.h"
 #include "base/string_util.h"
 #include "chrome/browser/history/top_sites.h"
+#include "chrome/common/chrome_paths.h"
 #include "chrome/browser/history/top_sites_database.h"
 #include "chrome/test/testing_profile.h"
+#include "chrome/tools/profiles/thumbnail-inl.h"
 #include "googleurl/src/gurl.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/skia/include/core/SkBitmap.h"
@@ -13,6 +16,9 @@
 
 namespace history {
 
+static const unsigned char kBlob[] =
+    "12346102356120394751634516591348710478123649165419234519234512349134";
+
 class TopSitesTest : public testing::Test {
  public:
   TopSitesTest() {
@@ -21,15 +27,30 @@ class TopSitesTest : public testing::Test {
   }
 
   TopSites& top_sites() { return *top_sites_; }
+  FilePath& file_name() { return file_name_; }
+  RefCountedBytes* google_thumbnail() { return google_thumbnail_; }
+  RefCountedBytes* random_thumbnail() { return random_thumbnail_; }
 
   virtual void SetUp() {
     profile_.reset(new TestingProfile);
     top_sites_ = new TopSites(profile_.get());
+
+    ASSERT_TRUE(temp_dir_.CreateUniqueTempDir());
+    file_name_ = temp_dir_.path().AppendASCII("TopSites.db");
+    EXPECT_TRUE(file_util::Delete(file_name_, false));
+
+    std::vector<unsigned char> random_data(kBlob, kBlob + sizeof(kBlob));
+    std::vector<unsigned char> google_data(kGoogleThumbnail,
+                                           kGoogleThumbnail +
+                                           sizeof(kGoogleThumbnail));
+    random_thumbnail_ = new RefCountedBytes(random_data);
+    google_thumbnail_ = new RefCountedBytes(google_data);
   }
 
   virtual void TearDown() {
     profile_.reset();
     top_sites_ = NULL;
+    EXPECT_TRUE(file_util::Delete(file_name_, false));
   }
 
   // Wrappers that allow private TopSites functions to be called from the
@@ -56,6 +77,10 @@ class TopSitesTest : public testing::Test {
  private:
   scoped_refptr<TopSites> top_sites_;
   scoped_ptr<TestingProfile> profile_;
+  ScopedTempDir temp_dir_;
+  FilePath file_name_;  // Database filename.
+  scoped_refptr<RefCountedBytes> google_thumbnail_;
+  scoped_refptr<RefCountedBytes> random_thumbnail_;
 
   DISALLOW_COPY_AND_ASSIGN(TopSitesTest);
 };
@@ -99,7 +124,7 @@ class MockTopSitesDatabaseImpl : public TopSitesDatabase {
   }
 
   virtual void SetPageThumbnail(const MostVisitedURL& url, int url_rank,
-                                const TopSites::Images thumbnail) {
+                                const TopSites::Images& thumbnail) {
     // Update the list of URLs
     // Check if this url is in the list, and at which position.
     MostVisitedURLList::iterator pos = std::find(top_sites_list_.begin(),
@@ -123,7 +148,7 @@ class MockTopSitesDatabaseImpl : public TopSitesDatabase {
 
   // Get a thumbnail for a given page. Returns true iff we have the thumbnail.
   virtual bool GetPageThumbnail(const MostVisitedURL& url,
-                                TopSites::Images* thumbnail) const {
+                                TopSites::Images* thumbnail) {
     std::map<GURL, TopSites::Images>::const_iterator found =
         thumbnails_map_.find(url.url);
     if (found == thumbnails_map_.end())
@@ -163,6 +188,16 @@ static void AppendMostVisitedURL(std::vector<MostVisitedURL>* list,
   list->push_back(mv);
 }
 
+// Returns true if t1 and t2 contain the same data.
+static bool ThumbnailsAreEqual(RefCountedBytes* t1,
+                               RefCountedBytes* t2) {
+  if (!t1 || !t2)
+    return false;
+  return std::equal(t1->data.begin(),
+                    t1->data.end(),
+                    t2->data.begin());
+}
+
 // Same as AppendMostVisitedURL except that it adds a redirect from the first
 // URL to the second.
 static void AppendMostVisitedURLWithRedirect(
@@ -305,7 +340,7 @@ TEST_F(TopSitesTest, GetMostVisited) {
   EXPECT_EQ(google, results[1].url);
 }
 
-TEST_F(TopSitesTest, ReadDatabase) {
+TEST_F(TopSitesTest, MockDatabase) {
   MockTopSitesDatabaseImpl* db = new MockTopSitesDatabaseImpl;
   // |db| is destroyed when the top_sites is destroyed in TearDown.
   top_sites().db_.reset(db);
@@ -362,4 +397,165 @@ TEST_F(TopSitesTest, ReadDatabase) {
   EXPECT_EQ(news_title, result[1].title);
 }
 
+// Test TopSitesDatabaseImpl.
+TEST_F(TopSitesTest, TopSitesDB) {
+  TopSitesDatabaseImpl db;
+
+  ASSERT_TRUE(db.Init(file_name()));
+
+  MostVisitedURL url;
+  GURL asdf_url("http://asdf.com");
+  string16 asdf_title(ASCIIToUTF16("ASDF"));
+  GURL google_url("http://google.com");
+  string16 google_title(ASCIIToUTF16("Google"));
+  GURL news_url("http://news.google.com");
+  string16 news_title(ASCIIToUTF16("Google News"));
+
+  url.url = asdf_url;
+  url.title = asdf_title;
+  url.redirects.push_back(url.url);
+  TopSites::Images thumbnail;
+  thumbnail.thumbnail = random_thumbnail();
+  // Add asdf at rank 0.
+  db.SetPageThumbnail(url, 0, thumbnail);
+
+  TopSites::Images result;
+  EXPECT_TRUE(db.GetPageThumbnail(url, &result));
+  EXPECT_EQ(thumbnail.thumbnail->data.size(), result.thumbnail->data.size());
+  EXPECT_TRUE(ThumbnailsAreEqual(thumbnail.thumbnail, result.thumbnail));
+
+  MostVisitedURLList urls = db.GetTopURLs();
+  ASSERT_EQ(1u, urls.size());
+  EXPECT_EQ(asdf_url, urls[0].url);
+  EXPECT_EQ(asdf_title, urls[0].title);
+
+  url.url = google_url;
+  url.title = google_title;
+
+  // Add google at rank 1 - no rank shifting.
+  db.SetPageThumbnail(url, 1, thumbnail);
+  urls = db.GetTopURLs();
+  ASSERT_EQ(2u, urls.size());
+  EXPECT_EQ(asdf_url, urls[0].url);
+  EXPECT_EQ(asdf_title, urls[0].title);
+  EXPECT_EQ(google_url, urls[1].url);
+  EXPECT_EQ(google_title, urls[1].title);
+
+  url.url = news_url;
+  url.title = news_title;
+
+  // Add news at rank 1 - shift google to rank 2.
+  db.SetPageThumbnail(url, 1, thumbnail);
+  urls = db.GetTopURLs();
+  ASSERT_EQ(3u, urls.size());
+  EXPECT_EQ(asdf_url, urls[0].url);
+  EXPECT_EQ(news_url, urls[1].url);
+  EXPECT_EQ(google_url, urls[2].url);
+
+  db.GetTopURLs();
+  // Move news at rank 0 - shift the rest up.
+  db.SetPageThumbnail(url, 0, thumbnail);
+  urls = db.GetTopURLs();
+  ASSERT_EQ(3u, urls.size());
+  EXPECT_EQ(news_url, urls[0].url);
+  EXPECT_EQ(asdf_url, urls[1].url);
+  EXPECT_EQ(google_url, urls[2].url);
+
+  // Move news at rank 2 - shift the rest down.
+  db.SetPageThumbnail(url, 2, thumbnail);
+  urls = db.GetTopURLs();
+  ASSERT_EQ(3u, urls.size());
+  EXPECT_EQ(asdf_url, urls[0].url);
+  EXPECT_EQ(google_url, urls[1].url);
+  EXPECT_EQ(news_url, urls[2].url);
+
+  // Delete asdf.
+  url.url = asdf_url;
+  db.RemoveURL(url);
+
+  urls = db.GetTopURLs();
+  ASSERT_EQ(2u, urls.size());
+  EXPECT_EQ(google_url, urls[0].url);
+  EXPECT_EQ(news_url, urls[1].url);
+}
+
+// Test TopSites with a real database.
+TEST_F(TopSitesTest, RealDatabase) {
+  TopSitesDatabaseImpl* db = new TopSitesDatabaseImpl;
+
+  ASSERT_TRUE(db->Init(file_name()));
+  // |db| is destroyed when the top_sites is destroyed in TearDown.
+  top_sites().db_.reset(db);
+  MostVisitedURL url;
+  GURL asdf_url("http://asdf.com");
+  string16 asdf_title(ASCIIToUTF16("ASDF"));
+  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"));
+
+  url.url = asdf_url;
+  url.title = asdf_title;
+  url.redirects.push_back(url.url);
+  TopSites::Images thumbnail;
+  thumbnail.thumbnail = random_thumbnail();
+  db->SetPageThumbnail(url, 0, thumbnail);
+
+  top_sites().ReadDatabase();
+
+  MostVisitedURLList result = top_sites().GetMostVisitedURLs();
+  ASSERT_EQ(1u, result.size());
+  EXPECT_EQ(asdf_url, result[0].url);
+  EXPECT_EQ(asdf_title, result[0].title);
+
+  RefCountedBytes* thumbnail_result;
+  top_sites().GetPageThumbnail(asdf_url, &thumbnail_result);
+  EXPECT_TRUE(thumbnail_result != NULL);
+  EXPECT_TRUE(ThumbnailsAreEqual(random_thumbnail(), thumbnail_result));
+
+  MostVisitedURL url2;
+  url2.url = google1_url;
+  url2.title = google_title;
+  url2.redirects.push_back(google1_url);
+  url2.redirects.push_back(google2_url);
+  url2.redirects.push_back(google3_url);
+
+  // Add new thumbnail at rank 0 and shift the other result to 1.
+  TopSites::Images g_thumbnail;
+  g_thumbnail.thumbnail = google_thumbnail();
+  db->SetPageThumbnail(url2, 0, g_thumbnail);
+
+  top_sites().ReadDatabase();
+
+  result = top_sites().GetMostVisitedURLs();
+  ASSERT_EQ(2u, result.size());
+  EXPECT_EQ(google1_url, result[0].url);
+  EXPECT_EQ(google_title, result[0].title);
+  top_sites().GetPageThumbnail(google1_url, &thumbnail_result);
+  EXPECT_TRUE(ThumbnailsAreEqual(google_thumbnail(), thumbnail_result));
+  ASSERT_EQ(3u, result[0].redirects.size());
+  EXPECT_EQ(google1_url, result[0].redirects[0]);
+  EXPECT_EQ(google2_url, result[0].redirects[1]);
+  EXPECT_EQ(google3_url, result[0].redirects[2]);
+
+  EXPECT_EQ(asdf_url, result[1].url);
+  EXPECT_EQ(asdf_title, result[1].title);
+
+  MockHistoryServiceImpl hs;
+  // Add one old, one new URL to the history.
+  hs.AppendMockPage(google1_url, google_title);
+  hs.AppendMockPage(news_url, news_title);
+  top_sites().SetMockHistoryService(&hs);
+
+  // This writes the new data to the DB.
+  top_sites().StartQueryForMostVisited();
+
+  result = db->GetTopURLs();
+  ASSERT_EQ(2u, result.size());
+  EXPECT_EQ(google_title, result[0].title);
+  EXPECT_EQ(news_title, result[1].title);
+}
+
 }  // namespace history