Detect removed files and reflect the state in chrome://downloads and the download shelf

- Invalidate the links of removed files in chrome://downloads page
- Label "Removed" for the removed files in the download shelf

BUG=29093
TEST=Observe that in chrome://downloads, the downloaded and then removed files are labeled "Removed" and have no links, Observe that in the download shelf, the downloaded and then removed files are labeled "Removed", DownloadManagerTest.*


Review URL: http://codereview.chromium.org/6905049

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@89148 0039d316-1c4b-4281-b951-d872f2087c98

18 files changed, 348 insertions, 72 deletions

diff --git a/chrome/app/generated_resources.grd b/chrome/app/generated_resources.grd
index 3f0d945..b78c394 100644
--- a/chrome/app/generated_resources.grd
+++ b/chrome/app/generated_resources.grd
@@ -2181,9 +2181,12 @@ Other platform defines such as use_titlecase are declared in build/common.gypi.
                desc="Temporary status shown when a user has clicked to open a downloaded file.">
         Opening <ph name="FILE">$1<ex>image.jpg</ex></ph>...
       </message>
-      <message name="IDS_DOWNLOAD_STATUS_CANCELED" desc="Canceled text.">
+      <message name="IDS_DOWNLOAD_STATUS_CANCELED" desc="Text that appears under the downloaded files that have been canceled.">
         Canceled
       </message>
+      <message name="IDS_DOWNLOAD_STATUS_REMOVED" desc="Text that appears under the downloaded files that have been removed.">
+        Removed
+      </message>
       <message name="IDS_DOWNLOAD_UNCONFIRMED_PREFIX" desc="The prefix used in the unconfirmed download file.">
         Unconfirmed
       </message>
@@ -2253,9 +2256,13 @@ Other platform defines such as use_titlecase are declared in build/common.gypi.
         </message>
       </if>
       <message name="IDS_DOWNLOAD_TAB_CANCELED"
-               desc="Cancel link text">
+               desc="Text that appears next to the downloaded files that have been canceled">
         Canceled
       </message>
+      <message name="IDS_DOWNLOAD_FILE_REMOVED"
+               desc="Text that appears next to the downloaded files that have been removed">
+        Removed
+      </message>
       <message name="IDS_DOWNLOAD_TAB_PROGRESS_STATUS_TIME_UNKNOWN"
                desc="The status text for a download in progress in the download manager. This includes information such as speed and received byte counts and is used when we do not know the remaining time">
         <ph name="SPEED">$1<ex>10kB/s</ex></ph> - <ph name="RECEIVED_AMOUNT">$2<ex>40kB</ex></ph>
diff --git a/chrome/browser/download/download_item.cc b/chrome/browser/download/download_item.cc
index 62aa272..1b2f7cf 100644
--- a/chrome/browser/download/download_item.cc
+++ b/chrome/browser/download/download_item.cc
@@ -132,6 +132,7 @@ DownloadItem::DownloadItem(DownloadManager* download_manager,
       download_manager_(download_manager),
       is_paused_(false),
       open_when_complete_(false),
+      file_externally_removed_(false),
       safety_state_(SAFE),
       auto_opened_(false),
       is_otr_(false),
@@ -173,6 +174,7 @@ DownloadItem::DownloadItem(DownloadManager* download_manager,
       download_manager_(download_manager),
       is_paused_(false),
       open_when_complete_(false),
+      file_externally_removed_(false),
       safety_state_(SAFE),
       auto_opened_(false),
       is_otr_(is_otr),
@@ -202,6 +204,7 @@ DownloadItem::DownloadItem(DownloadManager* download_manager,
       download_manager_(download_manager),
       is_paused_(false),
       open_when_complete_(false),
+      file_externally_removed_(false),
       safety_state_(SAFE),
       auto_opened_(false),
       is_otr_(is_otr),
@@ -242,8 +245,13 @@ void DownloadItem::UpdateObservers() {
   FOR_EACH_OBSERVER(Observer, observers_, OnDownloadUpdated(this));
 }
 
+bool DownloadItem::CanShowInFolder() {
+  return !IsCancelled() && !file_externally_removed_;
+}
+
 bool DownloadItem::CanOpenDownload() {
-  return !Extension::IsExtension(state_info_.target_name);
+  return !Extension::IsExtension(state_info_.target_name) &&
+    !file_externally_removed_;
 }
 
 bool DownloadItem::ShouldOpenFileBasedOnExtension() {
@@ -265,7 +273,12 @@ void DownloadItem::OpenDownload() {
 
   if (IsPartialDownload()) {
     open_when_complete_ = !open_when_complete_;
-  } else if (IsComplete()) {
+  } else if (IsComplete() && !file_externally_removed_) {
+    // Ideally, we want to detect errors in opening and report them, but we
+    // don't generally have the proper interface for that to the external
+    // program that opens the file.  So instead we spawn a check to update
+    // the UI if the file has been deleted in parallel with the open.
+    download_manager_->CheckForFileRemoval(this);
     opened_ = true;
     FOR_EACH_OBSERVER(Observer, observers_, OnDownloadOpened(this));
 
@@ -396,6 +409,11 @@ void DownloadItem::OnAllDataSaved(int64 size) {
   StopProgressTimer();
 }
 
+void DownloadItem::OnDownloadedFileRemoved() {
+  file_externally_removed_ = true;
+  UpdateObservers();
+}
+
 void DownloadItem::Completed() {
   // TODO(rdsmith): Change to DCHECK after http://crbug.com/85408 resolved.
   CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
diff --git a/chrome/browser/download/download_item.h b/chrome/browser/download/download_item.h
index ef262d6..9e501f2 100644
--- a/chrome/browser/download/download_item.h
+++ b/chrome/browser/download/download_item.h
@@ -135,7 +135,11 @@ class DownloadItem : public NotificationObserver {
                        const NotificationSource& source,
                        const NotificationDetails& details);
 
-  // Returns true if it is OK to open this download.
+  // Returns true if it is OK to open a folder which this file is inside.
+  bool CanShowInFolder();
+
+  // Returns true if it is OK to register the type of this file so that
+  // it opens automatically.
   bool CanOpenDownload();
 
   // Tests if a file type should be opened automatically.
@@ -170,13 +174,16 @@ class DownloadItem : public NotificationObserver {
   // when resuming a download (assuming the server supports byte ranges).
   void Cancel(bool update_history);
 
-  // Called when all data has been saved.  Only has display effects.
-  void OnAllDataSaved(int64 size);
-
   // Called by external code (SavePackage) using the DownloadItem interface
   // to display progress when the DownloadItem should be considered complete.
   void MarkAsComplete();
 
+  // Called when all data has been saved. Only has display effects.
+  void OnAllDataSaved(int64 size);
+
+  // Called when the downloaded file is removed.
+  void OnDownloadedFileRemoved();
+
   // Download operation had an error.
   // |size| is the amount of data received so far, and |os_error| is the error
   // code that the operation received.
@@ -278,6 +285,7 @@ class DownloadItem : public NotificationObserver {
   bool is_paused() const { return is_paused_; }
   bool open_when_complete() const { return open_when_complete_; }
   void set_open_when_complete(bool open) { open_when_complete_ = open; }
+  bool file_externally_removed() const { return file_externally_removed_; }
   SafetyState safety_state() const { return safety_state_; }
   void set_safety_state(SafetyState safety_state) {
     safety_state_ = safety_state;
@@ -432,6 +440,9 @@ class DownloadItem : public NotificationObserver {
   // A flag for indicating if the download should be opened at completion.
   bool open_when_complete_;
 
+  // A flag for indicating if the downloaded file is externally removed.
+  bool file_externally_removed_;
+
   // Indicates if the download is considered potentially safe or dangerous
   // (executable files are typically considered dangerous).
   SafetyState safety_state_;
diff --git a/chrome/browser/download/download_item_model.cc b/chrome/browser/download/download_item_model.cc
index bbac94b..9eae34f 100644
--- a/chrome/browser/download/download_item_model.cc
+++ b/chrome/browser/download/download_item_model.cc
@@ -82,7 +82,11 @@ string16 DownloadItemModel::GetStatusText() {
       }
       break;
     case DownloadItem::COMPLETE:
-      status_text.clear();
+      if (download_->file_externally_removed()) {
+        status_text = l10n_util::GetStringUTF16(IDS_DOWNLOAD_STATUS_REMOVED);
+      } else {
+        status_text.clear();
+      }
       break;
     case DownloadItem::CANCELLED:
       status_text = l10n_util::GetStringUTF16(IDS_DOWNLOAD_STATUS_CANCELED);
diff --git a/chrome/browser/download/download_manager.cc b/chrome/browser/download/download_manager.cc
index 8724641..0ba403a 100644
--- a/chrome/browser/download/download_manager.cc
+++ b/chrome/browser/download/download_manager.cc
@@ -274,6 +274,48 @@ void DownloadManager::StartDownload(int32 download_id) {
       NewCallback(this, &DownloadManager::CheckDownloadUrlDone));
 }
 
+void DownloadManager::CheckForHistoryFilesRemoval() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  for (DownloadMap::iterator it = history_downloads_.begin();
+       it != history_downloads_.end(); ++it) {
+    CheckForFileRemoval(it->second);
+  }
+}
+
+void DownloadManager::CheckForFileRemoval(DownloadItem* download_item) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  if (download_item->IsComplete() &&
+      !download_item->file_externally_removed()) {
+    BrowserThread::PostTask(
+        BrowserThread::FILE, FROM_HERE,
+        NewRunnableMethod(this,
+                          &DownloadManager::CheckForFileRemovalOnFileThread,
+                          download_item->db_handle(),
+                          download_item->GetTargetFilePath()));
+  }
+}
+
+void DownloadManager::CheckForFileRemovalOnFileThread(
+    int64 db_handle, const FilePath& path) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+  if (!file_util::PathExists(path)) {
+    BrowserThread::PostTask(
+        BrowserThread::UI, FROM_HERE,
+        NewRunnableMethod(this,
+                          &DownloadManager::OnFileRemovalDetected,
+                          db_handle));
+  }
+}
+
+void DownloadManager::OnFileRemovalDetected(int64 db_handle) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  DownloadMap::iterator it = history_downloads_.find(db_handle);
+  if (it != history_downloads_.end()) {
+    DownloadItem* download_item = it->second;
+    download_item->OnDownloadedFileRemoved();
+  }
+}
+
 void DownloadManager::CheckDownloadUrlDone(int32 download_id,
                                            bool is_dangerous_url) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
@@ -1085,6 +1127,7 @@ void DownloadManager::OnQueryDownloadEntriesComplete(
              << " download = " << download->DebugString(true);
   }
   NotifyModelChanged();
+  CheckForHistoryFilesRemoval();
 }
 
 // Once the new DownloadItem's creation info has been committed to the history
diff --git a/chrome/browser/download/download_manager.h b/chrome/browser/download/download_manager.h
index 58d13cf..38a5ec6 100644
--- a/chrome/browser/download/download_manager.h
+++ b/chrome/browser/download/download_manager.h
@@ -235,6 +235,16 @@ class DownloadManager
   // Called when the user has validated the download of a dangerous file.
   void DangerousDownloadValidated(DownloadItem* download);
 
+  // Checks whether downloaded files still exist. Updates state of downloads
+  // that refer to removed files. The check runs in the background and may
+  // finish asynchronously after this method returns.
+  void CheckForHistoryFilesRemoval();
+
+  // Checks whether a downloaded file still exists and updates the file's state
+  // if the file is already removed. The check runs in the background and may
+  // finish asynchronously after this method returns.
+  void CheckForFileRemoval(DownloadItem* download_item);
+
   // Callback function after url is checked with safebrowsing service.
   void CheckDownloadUrlDone(int32 download_id, bool is_dangerous_url);
 
@@ -283,6 +293,14 @@ class DownloadManager
 
   virtual ~DownloadManager();
 
+  // Called on the FILE thread to check the existence of a downloaded file.
+  void CheckForFileRemovalOnFileThread(int64 db_handle, const FilePath& path);
+
+  // Called on the UI thread if the FILE thread detects the removal of
+  // the downloaded file. The UI thread updates the state of the file
+  // and then notifies this update to the file's observer.
+  void OnFileRemovalDetected(int64 db_handle);
+
   // Called on the download thread to check whether the suggested file path
   // exists.  We don't check if the file exists on the UI thread to avoid UI
   // stalls from interacting with the file system.
diff --git a/chrome/browser/download/download_manager_unittest.cc b/chrome/browser/download/download_manager_unittest.cc
index 0e947d1..8b6fcfe 100644
--- a/chrome/browser/download/download_manager_unittest.cc
+++ b/chrome/browser/download/download_manager_unittest.cc
@@ -6,14 +6,19 @@
 #include <set>
 
 #include "base/file_util.h"
+#include "base/i18n/number_formatting.h"
+#include "base/i18n/rtl.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/stl_util-inl.h"
 #include "base/string_util.h"
+#include "base/string16.h"
+#include "base/utf_string_conversions.h"
 #include "build/build_config.h"
 #include "chrome/browser/download/download_create_info.h"
 #include "chrome/browser/download/download_file.h"
 #include "chrome/browser/download/download_file_manager.h"
 #include "chrome/browser/download/download_item.h"
+#include "chrome/browser/download/download_item_model.h"
 #include "chrome/browser/download/download_manager.h"
 #include "chrome/browser/download/download_prefs.h"
 #include "chrome/browser/download/download_status_updater.h"
@@ -23,9 +28,11 @@
 #include "chrome/common/pref_names.h"
 #include "chrome/test/testing_profile.h"
 #include "content/browser/browser_thread.h"
+#include "grit/generated_resources.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gmock_mutant.h"
 #include "testing/gtest/include/gtest/gtest.h"
+#include "ui/base/l10n/l10n_util.h"
 
 class DownloadManagerTest : public testing::Test {
  public:
@@ -396,6 +403,7 @@ TEST_F(DownloadManagerTest, DownloadInterruptTest) {
   info->download_id = static_cast<int>(0);
   info->prompt_user_for_save_location = false;
   info->url_chain.push_back(GURL());
+  info->total_bytes = static_cast<int64>(kTestDataLen);
   const FilePath new_path(FILE_PATH_LITERAL("foo.zip"));
   const FilePath cr_path(download_util::GetCrDownloadPath(new_path));
 
@@ -413,6 +421,8 @@ TEST_F(DownloadManagerTest, DownloadInterruptTest) {
 
   DownloadItem* download = GetActiveDownloadItem(0);
   ASSERT_TRUE(download != NULL);
+  scoped_ptr<DownloadItemModel> download_item_model(
+      new DownloadItemModel(download));
 
   EXPECT_EQ(DownloadItem::IN_PROGRESS, download->state());
   scoped_ptr<ItemObserver> observer(new ItemObserver(download));
@@ -423,11 +433,11 @@ TEST_F(DownloadManagerTest, DownloadInterruptTest) {
   message_loop_.RunAllPending();
   EXPECT_TRUE(GetActiveDownloadItem(0) != NULL);
 
-  OnDownloadError(0, 1024, -6);
+  int64 error_size = 3;
+  OnDownloadError(0, error_size, -6);
   message_loop_.RunAllPending();
 
   EXPECT_TRUE(GetActiveDownloadItem(0) == NULL);
-  EXPECT_EQ(DownloadItem::INTERRUPTED, download->state());
   EXPECT_TRUE(observer->hit_state(DownloadItem::IN_PROGRESS));
   EXPECT_TRUE(observer->hit_state(DownloadItem::INTERRUPTED));
   EXPECT_FALSE(observer->hit_state(DownloadItem::COMPLETE));
@@ -435,10 +445,19 @@ TEST_F(DownloadManagerTest, DownloadInterruptTest) {
   EXPECT_FALSE(observer->hit_state(DownloadItem::REMOVING));
   EXPECT_TRUE(observer->was_updated());
   EXPECT_FALSE(observer->was_opened());
+  EXPECT_FALSE(download->file_externally_removed());
+  EXPECT_EQ(DownloadItem::INTERRUPTED, download->state());
+  DataUnits amount_units = GetByteDisplayUnits(kTestDataLen);
+  const string16 simple_size = FormatBytes(error_size, amount_units, false);
+  string16 simple_total = base::i18n::GetDisplayStringInLTRDirectionality(
+      FormatBytes(kTestDataLen, amount_units, true));
+  EXPECT_EQ(download_item_model->GetStatusText(),
+            l10n_util::GetStringFUTF16(IDS_DOWNLOAD_STATUS_INTERRUPTED,
+                                       simple_size,
+                                       simple_total));
 
   download->Cancel(true);
 
-  EXPECT_EQ(DownloadItem::INTERRUPTED, download->state());
   EXPECT_TRUE(observer->hit_state(DownloadItem::IN_PROGRESS));
   EXPECT_TRUE(observer->hit_state(DownloadItem::INTERRUPTED));
   EXPECT_FALSE(observer->hit_state(DownloadItem::COMPLETE));
@@ -446,6 +465,10 @@ TEST_F(DownloadManagerTest, DownloadInterruptTest) {
   EXPECT_FALSE(observer->hit_state(DownloadItem::REMOVING));
   EXPECT_TRUE(observer->was_updated());
   EXPECT_FALSE(observer->was_opened());
+  EXPECT_FALSE(download->file_externally_removed());
+  EXPECT_EQ(DownloadItem::INTERRUPTED, download->state());
+  EXPECT_EQ(download->received_bytes(), error_size);
+  EXPECT_EQ(download->total_bytes(), static_cast<int64>(kTestDataLen));
 }
 
 TEST_F(DownloadManagerTest, DownloadCancelTest) {
@@ -478,6 +501,8 @@ TEST_F(DownloadManagerTest, DownloadCancelTest) {
 
   DownloadItem* download = GetActiveDownloadItem(0);
   ASSERT_TRUE(download != NULL);
+  scoped_ptr<DownloadItemModel> download_item_model(
+      new DownloadItemModel(download));
 
   EXPECT_EQ(DownloadItem::IN_PROGRESS, download->state());
   scoped_ptr<ItemObserver> observer(new ItemObserver(download));
@@ -499,6 +524,10 @@ TEST_F(DownloadManagerTest, DownloadCancelTest) {
   EXPECT_FALSE(observer->hit_state(DownloadItem::REMOVING));
   EXPECT_TRUE(observer->was_updated());
   EXPECT_FALSE(observer->was_opened());
+  EXPECT_FALSE(download->file_externally_removed());
+  EXPECT_EQ(DownloadItem::CANCELLED, download->state());
+  EXPECT_EQ(download_item_model->GetStatusText(),
+            l10n_util::GetStringUTF16(IDS_DOWNLOAD_STATUS_CANCELED));
 
   EXPECT_FALSE(file_util::PathExists(new_path));
   EXPECT_FALSE(file_util::PathExists(cr_path));
@@ -544,6 +573,8 @@ TEST_F(DownloadManagerTest, DownloadOverwriteTest) {
 
   DownloadItem* download = GetActiveDownloadItem(0);
   ASSERT_TRUE(download != NULL);
+  scoped_ptr<DownloadItemModel> download_item_model(
+      new DownloadItemModel(download));
 
   EXPECT_EQ(DownloadItem::IN_PROGRESS, download->state());
   scoped_ptr<ItemObserver> observer(new ItemObserver(download));
@@ -579,7 +610,9 @@ TEST_F(DownloadManagerTest, DownloadOverwriteTest) {
   EXPECT_FALSE(observer->hit_state(DownloadItem::REMOVING));
   EXPECT_TRUE(observer->was_updated());
   EXPECT_FALSE(observer->was_opened());
+  EXPECT_FALSE(download->file_externally_removed());
   EXPECT_EQ(DownloadItem::COMPLETE, download->state());
+  EXPECT_EQ(download_item_model->GetStatusText(), ASCIIToUTF16(""));
 
   EXPECT_TRUE(file_util::PathExists(new_path));
   EXPECT_FALSE(file_util::PathExists(cr_path));
@@ -588,3 +621,95 @@ TEST_F(DownloadManagerTest, DownloadOverwriteTest) {
   EXPECT_TRUE(file_util::ReadFileToString(new_path, &file_contents));
   EXPECT_EQ(std::string(kTestData), file_contents);
 }
+
+TEST_F(DownloadManagerTest, DownloadRemoveTest) {
+  using ::testing::_;
+  using ::testing::CreateFunctor;
+  using ::testing::Invoke;
+  using ::testing::Return;
+
+  // Create a temporary directory.
+  ScopedTempDir temp_dir_;
+  ASSERT_TRUE(temp_dir_.CreateUniqueTempDir());
+
+  // File names we're using.
+  const FilePath new_path(temp_dir_.path().AppendASCII("foo.txt"));
+  const FilePath cr_path(download_util::GetCrDownloadPath(new_path));
+  EXPECT_FALSE(file_util::PathExists(new_path));
+
+  // Normally, the download system takes ownership of info, and is
+  // responsible for deleting it.  In these unit tests, however, we
+  // don't call the function that deletes it, so we do so ourselves.
+  scoped_ptr<DownloadCreateInfo> info(new DownloadCreateInfo);
+  info->download_id = static_cast<int>(0);
+  info->prompt_user_for_save_location = true;
+  info->url_chain.push_back(GURL());
+
+  download_manager_->CreateDownloadItem(info.get());
+
+  DownloadItem* download = GetActiveDownloadItem(0);
+  ASSERT_TRUE(download != NULL);
+  scoped_ptr<DownloadItemModel> download_item_model(
+      new DownloadItemModel(download));
+
+  EXPECT_EQ(DownloadItem::IN_PROGRESS, download->state());
+  scoped_ptr<ItemObserver> observer(new ItemObserver(download));
+
+  // Create and initialize the download file.  We're bypassing the first part
+  // of the download process and skipping to the part after the final file
+  // name has been chosen, so we need to initialize the download file
+  // properly.
+  DownloadFile* download_file(
+      new DownloadFile(info.get(), download_manager_));
+  download_file->Rename(cr_path);
+  // This creates the .crdownload version of the file.
+  download_file->Initialize(false);
+  // |download_file| is owned by DownloadFileManager.
+  AddDownloadToFileManager(info->download_id, download_file);
+
+  ContinueDownloadWithPath(download, new_path);
+  message_loop_.RunAllPending();
+  EXPECT_TRUE(GetActiveDownloadItem(0) != NULL);
+
+  download_file->AppendDataToFile(kTestData, kTestDataLen);
+
+  // Finish the download.
+  OnAllDataSaved(0, kTestDataLen, "");
+  message_loop_.RunAllPending();
+
+  // Download is complete.
+  EXPECT_TRUE(GetActiveDownloadItem(0) == NULL);
+  EXPECT_TRUE(observer->hit_state(DownloadItem::IN_PROGRESS));
+  EXPECT_FALSE(observer->hit_state(DownloadItem::CANCELLED));
+  EXPECT_FALSE(observer->hit_state(DownloadItem::INTERRUPTED));
+  EXPECT_TRUE(observer->hit_state(DownloadItem::COMPLETE));
+  EXPECT_FALSE(observer->hit_state(DownloadItem::REMOVING));
+  EXPECT_TRUE(observer->was_updated());
+  EXPECT_FALSE(observer->was_opened());
+  EXPECT_FALSE(download->file_externally_removed());
+  EXPECT_EQ(DownloadItem::COMPLETE, download->state());
+  EXPECT_EQ(download_item_model->GetStatusText(), ASCIIToUTF16(""));
+
+  EXPECT_TRUE(file_util::PathExists(new_path));
+  EXPECT_FALSE(file_util::PathExists(cr_path));
+
+  // Remove the downloaded file.
+  ASSERT_TRUE(file_util::Delete(new_path, false));
+  download->OnDownloadedFileRemoved();
+  message_loop_.RunAllPending();
+
+  EXPECT_TRUE(GetActiveDownloadItem(0) == NULL);
+  EXPECT_TRUE(observer->hit_state(DownloadItem::IN_PROGRESS));
+  EXPECT_FALSE(observer->hit_state(DownloadItem::CANCELLED));
+  EXPECT_FALSE(observer->hit_state(DownloadItem::INTERRUPTED));
+  EXPECT_TRUE(observer->hit_state(DownloadItem::COMPLETE));
+  EXPECT_FALSE(observer->hit_state(DownloadItem::REMOVING));
+  EXPECT_TRUE(observer->was_updated());
+  EXPECT_FALSE(observer->was_opened());
+  EXPECT_TRUE(download->file_externally_removed());
+  EXPECT_EQ(DownloadItem::COMPLETE, download->state());
+  EXPECT_EQ(download_item_model->GetStatusText(),
+            l10n_util::GetStringUTF16(IDS_DOWNLOAD_STATUS_REMOVED));
+
+  EXPECT_FALSE(file_util::PathExists(new_path));
+}
diff --git a/chrome/browser/download/download_shelf_context_menu.cc b/chrome/browser/download/download_shelf_context_menu.cc
index d019d7a..f1a42b7 100644
--- a/chrome/browser/download/download_shelf_context_menu.cc
+++ b/chrome/browser/download/download_shelf_context_menu.cc
@@ -26,7 +26,7 @@ bool DownloadShelfContextMenu::IsCommandIdEnabled(int command_id) const {
   switch (command_id) {
     case SHOW_IN_FOLDER:
     case OPEN_WHEN_COMPLETE:
-      return !download_item_->IsCancelled();
+      return download_item_->CanShowInFolder();
     case ALWAYS_OPEN_TYPE:
       return download_item_->CanOpenDownload();
     case CANCEL:
diff --git a/chrome/browser/download/download_util.cc b/chrome/browser/download/download_util.cc
index 88801ea..cf8d1c4 100644
--- a/chrome/browser/download/download_util.cc
+++ b/chrome/browser/download/download_util.cc
@@ -665,6 +665,8 @@ DictionaryValue* CreateDownloadItemValue(DownloadItem* download, int id) {
   file_value->SetString("url", download->GetURL().spec());
   file_value->SetBoolean("otr", download->is_otr());
   file_value->SetInteger("total", static_cast<int>(download->total_bytes()));
+  file_value->SetBoolean("file_externally_removed",
+                         download->file_externally_removed());
 
   if (download->IsInProgress()) {
     if (download->safety_state() == DownloadItem::DANGEROUS) {
@@ -701,11 +703,10 @@ DictionaryValue* CreateDownloadItemValue(DownloadItem* download, int id) {
   } else if (download->IsCancelled()) {
     file_value->SetString("state", "CANCELLED");
   } else if (download->IsComplete()) {
-    if (download->safety_state() == DownloadItem::DANGEROUS) {
+    if (download->safety_state() == DownloadItem::DANGEROUS)
       file_value->SetString("state", "DANGEROUS");
-    } else {
+    else
       file_value->SetString("state", "COMPLETE");
-    }
   } else if (download->state() == DownloadItem::REMOVING) {
     file_value->SetString("state", "REMOVING");
   } else {
diff --git a/chrome/browser/resources/downloads.js b/chrome/browser/resources/downloads.js
index 693685e..3c344a8 100644
--- a/chrome/browser/resources/downloads.js
+++ b/chrome/browser/resources/downloads.js
@@ -329,6 +329,7 @@ Download.prototype.update = function(download) {
   this.fileName_ = download.file_name;
   this.url_ = download.url;
   this.state_ = download.state;
+  this.fileExternallyRemoved_ = download.file_externally_removed;
   this.dangerType_ = download.danger_type;
 
   this.since_ = download.since_string;
@@ -351,19 +352,24 @@ Download.prototype.update = function(download) {
   } else {
     this.nodeImg_.src = 'chrome://fileicon/' + this.filePath_;
 
-    if (this.state_ == Download.States.COMPLETE) {
+    if (this.state_ == Download.States.COMPLETE &&
+        !this.fileExternallyRemoved_) {
       this.nodeFileLink_.innerHTML = this.fileName_;
       this.nodeFileLink_.href = this.filePath_;
     } else {
       this.nodeFileName_.innerHTML = this.fileName_;
     }
 
-    showInline(this.nodeFileLink_, this.state_ == Download.States.COMPLETE);
+    showInline(this.nodeFileLink_,
+               this.state_ == Download.States.COMPLETE &&
+                   !this.fileExternallyRemoved_);
     // nodeFileName_ has to be inline-block to avoid the 'interaction' with
     // nodeStatus_. If both are inline, it appears that their text contents
     // are merged before the bidi algorithm is applied leading to an
     // undesirable reordering. http://crbug.com/13216
-    showInlineBlock(this.nodeFileName_, this.state_ != Download.States.COMPLETE);
+    showInlineBlock(this.nodeFileName_,
+                    this.state_ != Download.States.COMPLETE ||
+                        this.fileExternallyRemoved_);
 
     if (this.state_ == Download.States.IN_PROGRESS) {
       this.nodeProgressForeground_.style.display = 'block';
@@ -396,7 +402,9 @@ Download.prototype.update = function(download) {
     }
 
     if (this.controlShow_) {
-      showInline(this.controlShow_, this.state_ == Download.States.COMPLETE);
+      showInline(this.controlShow_,
+                 this.state_ == Download.States.COMPLETE &&
+                     !this.fileExternallyRemoved_);
     }
     showInline(this.controlRetry_, this.state_ == Download.States.CANCELLED);
     this.controlRetry_.href = this.url_;
@@ -457,7 +465,8 @@ Download.prototype.getStatusText_ = function() {
     case Download.States.INTERRUPTED:
       return localStrings.getString('status_interrupted');
     case Download.States.COMPLETE:
-      return '';
+      return this.fileExternallyRemoved_ ?
+          localStrings.getString('status_removed') : '';
   }
 }
 
@@ -532,7 +541,15 @@ Download.prototype.cancel_ = function() {
 // Page:
 var downloads, localStrings, resultsTimeout;
 
+/**
+ * The FIFO array that stores updates of download files to be appeared
+ * on the download page. It is guaranteed that the updates in this array
+ * are reflected to the download page in a FIFO order.
+*/
+var fifo_results;
+
 function load() {
+  fifo_results = new Array();
   localStrings = new LocalStrings();
   downloads = new Downloads();
   $('term').focus();
@@ -541,12 +558,14 @@ function load() {
 }
 
 function setSearch(searchText) {
+  fifo_results.length = 0;
   downloads.clear();
   downloads.setSearchText(searchText);
   chrome.send('getDownloads', [searchText.toString()]);
 }
 
 function clearAll() {
+  fifo_results.length = 0;
   downloads.clear();
   downloads.setSearchText('');
   chrome.send('clearAll', []);
@@ -563,6 +582,7 @@ function downloadsList(results) {
   if (resultsTimeout)
     clearTimeout(resultsTimeout);
   window.console.log('results');
+  fifo_results.length = 0;
   downloads.clear();
   downloadUpdated(results);
   downloads.updateSummary();
@@ -576,13 +596,23 @@ function downloadUpdated(results) {
   if (!downloads)
     return;
 
+  fifo_results = fifo_results.concat(results);
+  tryDownloadUpdatedPeriodically();
+}
+
+/**
+ * Try to reflect as much updates as possible within 50ms.
+ * This function is scheduled again and again until all updates are reflected.
+ */
+function tryDownloadUpdatedPeriodically() {
   var start = Date.now();
-  for (var i = 0; i < results.length; i++) {
-    downloads.updated(results[i]);
+  while (fifo_results.length) {
+    var result = fifo_results.shift();
+    downloads.updated(result);
     // Do as much as we can in 50ms.
     if (Date.now() - start > 50) {
       clearTimeout(resultsTimeout);
-      resultsTimeout = setTimeout(downloadUpdated, 5, results.slice(i + 1));
+      resultsTimeout = setTimeout(tryDownloadUpdatedPeriodically, 5);
       break;
     }
   }
diff --git a/chrome/browser/ui/cocoa/download/download_item_cell.h b/chrome/browser/ui/cocoa/download/download_item_cell.h
index 91bceb5..dbb79b4 100644
--- a/chrome/browser/ui/cocoa/download/download_item_cell.h
+++ b/chrome/browser/ui/cocoa/download/download_item_cell.h
@@ -43,6 +43,7 @@ enum DownloadItemMousePosition {
   BOOL isStatusTextVisible_;
   CGFloat titleY_;
   CGFloat statusAlpha_;
+  scoped_nsobject<NSAnimation> showStatusAnimation_;
   scoped_nsobject<NSAnimation> hideStatusAnimation_;
 
   scoped_ptr<ui::ThemeProvider> themeProvider_;
diff --git a/chrome/browser/ui/cocoa/download/download_item_cell.mm b/chrome/browser/ui/cocoa/download/download_item_cell.mm
index 234dc10..3e20cd0 100644
--- a/chrome/browser/ui/cocoa/download/download_item_cell.mm
+++ b/chrome/browser/ui/cocoa/download/download_item_cell.mm
@@ -68,6 +68,7 @@ const CGFloat kDropdownArrowHeight = 3;
 const CGFloat kDropdownAreaY = -2;
 
 // Duration of the two-lines-to-one-line animation, in seconds.
+NSTimeInterval kShowStatusDuration = 0.3;
 NSTimeInterval kHideStatusDuration = 0.3;
 
 // Duration of the 'download complete' animation, in seconds.
@@ -87,6 +88,7 @@ const int kInterruptedAnimationDuration = 2.5;
 
 @interface DownloadItemCell(Private)
 - (void)updateTrackingAreas:(id)sender;
+- (void)showSecondaryTitle;
 - (void)hideSecondaryTitle;
 - (void)animation:(NSAnimation*)animation
        progressed:(NSAnimationProgress)progress;
@@ -142,6 +144,8 @@ const int kInterruptedAnimationDuration = 2.5;
   [[NSNotificationCenter defaultCenter] removeObserver:self];
   if ([completionAnimation_ isAnimating])
     [completionAnimation_ stopAnimation];
+  if ([showStatusAnimation_ isAnimating])
+    [showStatusAnimation_ stopAnimation];
   if ([hideStatusAnimation_ isAnimating])
     [hideStatusAnimation_ stopAnimation];
   if (trackingAreaButton_) {
@@ -170,6 +174,7 @@ const int kInterruptedAnimationDuration = 2.5;
     // Set status text.
     NSString* statusString = base::SysUTF16ToNSString(statusText);
     [self setSecondaryTitle:statusString];
+    [self showSecondaryTitle];
     isStatusTextVisible_ = YES;
   }
 
@@ -593,6 +598,21 @@ const int kInterruptedAnimationDuration = 2.5;
                     kImageHeight);
 }
 
+- (void)showSecondaryTitle {
+  if (!isStatusTextVisible_) {
+    // No core animation -- text in CA layers is not subpixel antialiased :-/
+    showStatusAnimation_.reset([[DownloadItemCellAnimation alloc]
+        initWithDownloadItemCell:self
+                        duration:kShowStatusDuration
+                  animationCurve:NSAnimationEaseIn]);
+    [showStatusAnimation_.get() setDelegate:self];
+    [showStatusAnimation_.get() startAnimation];
+  } else {
+    // If the status line continues to be visible, don't show an animation
+    [self animation:nil progressed:0.0];
+  }
+}
+
 - (void)hideSecondaryTitle {
   if (isStatusTextVisible_) {
     // No core animation -- text in CA layers is not subpixel antialiased :-/
@@ -611,7 +631,12 @@ const int kInterruptedAnimationDuration = 2.5;
 
 - (void)animation:(NSAnimation*)animation
       progressed:(NSAnimationProgress)progress {
-  if (animation == hideStatusAnimation_ || animation == nil) {
+  if (animation == showStatusAnimation_) {
+    titleY_ = (1 - progress)*kPrimaryTextOnlyPosTop +
+      kPrimaryTextPosTop;
+    statusAlpha_ = progress;
+    [[self controlView] setNeedsDisplay:YES];
+  } else if (animation == hideStatusAnimation_ || animation == nil) {
     titleY_ = progress*kPrimaryTextOnlyPosTop +
         (1 - progress)*kPrimaryTextPosTop;
     statusAlpha_ = 1 - progress;
@@ -622,7 +647,9 @@ const int kInterruptedAnimationDuration = 2.5;
 }
 
 - (void)animationDidEnd:(NSAnimation *)animation {
-  if (animation == hideStatusAnimation_)
+  if (animation == showStatusAnimation_)
+    showStatusAnimation_.reset();
+  else if (animation == hideStatusAnimation_)
     hideStatusAnimation_.reset();
   else if (animation == completionAnimation_)
     completionAnimation_.reset();
diff --git a/chrome/browser/ui/gtk/download/download_item_gtk.cc b/chrome/browser/ui/gtk/download/download_item_gtk.cc
index 31b4303..c927494 100644
--- a/chrome/browser/ui/gtk/download/download_item_gtk.cc
+++ b/chrome/browser/ui/gtk/download/download_item_gtk.cc
@@ -125,23 +125,18 @@ DownloadItemGtk::DownloadItemGtk(DownloadShelfGtk* parent_shelf,
   g_object_unref(no_padding_style);
 
   name_label_ = gtk_label_new(NULL);
-
-  UpdateNameLabel();
-
-  status_label_ = gtk_label_new(NULL);
-  g_signal_connect(status_label_, "destroy",
-                   G_CALLBACK(gtk_widget_destroyed), &status_label_);
   // Left align and vertically center the labels.
   gtk_misc_set_alignment(GTK_MISC(name_label_), 0, 0.5);
-  gtk_misc_set_alignment(GTK_MISC(status_label_), 0, 0.5);
   // Until we switch to vector graphics, force the font size.
   gtk_util::ForceFontSizePixels(name_label_, kTextSize);
-  gtk_util::ForceFontSizePixels(status_label_, kTextSize);
+
+  UpdateNameLabel();
+
+  status_label_ = NULL;
 
   // Stack the labels on top of one another.
-  GtkWidget* text_stack = gtk_vbox_new(FALSE, 0);
-  gtk_box_pack_start(GTK_BOX(text_stack), name_label_, TRUE, TRUE, 0);
-  gtk_box_pack_start(GTK_BOX(text_stack), status_label_, FALSE, FALSE, 0);
+  text_stack_ = gtk_vbox_new(FALSE, 0);
+  gtk_box_pack_start(GTK_BOX(text_stack_), name_label_, TRUE, TRUE, 0);
 
   // We use a GtkFixed because we don't want it to have its own window.
   // This choice of widget is not critically important though.
@@ -157,7 +152,7 @@ DownloadItemGtk::DownloadItemGtk(DownloadShelfGtk* parent_shelf,
   GtkWidget* body_hbox = gtk_hbox_new(FALSE, 0);
   gtk_container_add(GTK_CONTAINER(body_.get()), body_hbox);
   gtk_box_pack_start(GTK_BOX(body_hbox), progress_area_.get(), FALSE, FALSE, 0);
-  gtk_box_pack_start(GTK_BOX(body_hbox), text_stack, TRUE, TRUE, 0);
+  gtk_box_pack_start(GTK_BOX(body_hbox), text_stack_, TRUE, TRUE, 0);
 
   menu_button_ = gtk_button_new();
   gtk_widget_set_app_paintable(menu_button_, TRUE);
@@ -349,19 +344,7 @@ void DownloadItemGtk::OnDownloadUpdated(DownloadItem* download) {
       NOTREACHED();
   }
 
-  // Now update the status label. We may have already removed it; if so, we
-  // do nothing.
-  if (!status_label_) {
-    return;
-  }
-
   status_text_ = UTF16ToUTF8(download_model_->GetStatusText());
-  // Remove the status text label.
-  if (status_text_.empty()) {
-    gtk_widget_destroy(status_label_);
-    return;
-  }
-
   UpdateStatusLabel(status_text_);
 }
 
@@ -498,8 +481,26 @@ void DownloadItemGtk::UpdateNameLabel() {
 }
 
 void DownloadItemGtk::UpdateStatusLabel(const std::string& status_text) {
-  if (!status_label_)
+  // If |status_text| is empty, only |name_label_| is displayed at the
+  // vertical center of |text_stack_|. Otherwise, |name_label_| is displayed
+  // on the upper half of |text_stack_| and |status_label_| is displayed
+  // on the lower half of |text_stack_|.
+  if (status_text.empty() && status_label_) {
+    gtk_widget_destroy(status_label_);
     return;
+  }
+  if (!status_label_) {
+    status_label_ = gtk_label_new(NULL);
+    g_signal_connect(status_label_, "destroy",
+                     G_CALLBACK(gtk_widget_destroyed), &status_label_);
+    // Left align and vertically center the labels.
+    gtk_misc_set_alignment(GTK_MISC(status_label_), 0, 0.5);
+    // Until we switch to vector graphics, force the font size.
+    gtk_util::ForceFontSizePixels(status_label_, kTextSize);
+
+    gtk_box_pack_start(GTK_BOX(text_stack_), status_label_, FALSE, FALSE, 0);
+    gtk_widget_show_all(hbox_.get());
+  }
 
   GdkColor text_color;
   if (!theme_service_->UsingNativeTheme()) {
@@ -785,7 +786,6 @@ gboolean DownloadItemGtk::OnButtonPress(GtkWidget* button,
     ShowPopupMenu(NULL, event);
     return TRUE;
   }
-
   return FALSE;
 }
 
@@ -833,7 +833,6 @@ gboolean DownloadItemGtk::OnMenuButtonPressEvent(GtkWidget* button,
     gtk_widget_queue_draw(button);
     return TRUE;
   }
-
   return FALSE;
 }
 
diff --git a/chrome/browser/ui/gtk/download/download_item_gtk.h b/chrome/browser/ui/gtk/download/download_item_gtk.h
index 76f9dc4..d66fce6 100644
--- a/chrome/browser/ui/gtk/download/download_item_gtk.h
+++ b/chrome/browser/ui/gtk/download/download_item_gtk.h
@@ -160,6 +160,9 @@ class DownloadItemGtk : public DownloadItem::Observer,
   // animation.
   OwnedWidgetGtk body_;
 
+  // The widget that contains the texts of |name_label_| and |status_label_|.
+  GtkWidget* text_stack_;
+
   // The GtkLabel that holds the download title text.
   GtkWidget* name_label_;
 
diff --git a/chrome/browser/ui/views/download/download_item_view.cc b/chrome/browser/ui/views/download/download_item_view.cc
index 62a12e5..5097c7a 100644
--- a/chrome/browser/ui/views/download/download_item_view.cc
+++ b/chrome/browser/ui/views/download/download_item_view.cc
@@ -86,7 +86,6 @@ DownloadItemView::DownloadItemView(DownloadItem* download,
     parent_(parent),
     status_text_(UTF16ToWide(
         l10n_util::GetStringUTF16(IDS_DOWNLOAD_STATUS_STARTING))),
-    show_status_text_(true),
     body_state_(NORMAL),
     drop_down_state_(NORMAL),
     progress_angle_(download_util::kStartAngleDegrees),
@@ -355,8 +354,6 @@ void DownloadItemView::OnDownloadUpdated(DownloadItem* download) {
       complete_animation_->SetSlideDuration(kInterruptedAnimationDurationMs);
       complete_animation_->SetTweenType(ui::Tween::LINEAR);
       complete_animation_->Show();
-      if (status_text.empty())
-        show_status_text_ = false;
       SchedulePaint();
       LoadIcon();
       break;
@@ -370,8 +367,6 @@ void DownloadItemView::OnDownloadUpdated(DownloadItem* download) {
       complete_animation_->SetSlideDuration(kCompleteAnimationDurationMs);
       complete_animation_->SetTweenType(ui::Tween::LINEAR);
       complete_animation_->Show();
-      if (status_text.empty())
-        show_status_text_ = false;
       SchedulePaint();
       LoadIcon();
       break;
@@ -723,7 +718,7 @@ void DownloadItemView::OnPaint(gfx::Canvas* canvas) {
 
   // Draw status before button image to effectively lighten text.
   if (!IsDangerousMode()) {
-    if (show_status_text_) {
+    if (!status_text_.empty()) {
       int mirrored_x = GetMirroredXWithWidthInView(
           download_util::kSmallProgressIconSize, kTextWidth);
       // Add font_.height() to compensate for title, which is drawn later.
@@ -856,8 +851,8 @@ void DownloadItemView::OnPaint(gfx::Canvas* canvas) {
     SkColor file_name_color = GetThemeProvider()->GetColor(
         ThemeService::COLOR_BOOKMARK_TEXT);
     int y =
-        box_y_ + (show_status_text_ ? kVerticalPadding :
-                                      (box_height_ - font_.GetHeight()) / 2);
+        box_y_ + (status_text_.empty() ?
+                  ((box_height_ - font_.GetHeight()) / 2) : kVerticalPadding);
 
     // Draw the file's name.
     canvas->DrawStringInt(filename, font_,
diff --git a/chrome/browser/ui/views/download/download_item_view.h b/chrome/browser/ui/views/download/download_item_view.h
index 4fe8f46..3a4d6de 100644
--- a/chrome/browser/ui/views/download/download_item_view.h
+++ b/chrome/browser/ui/views/download/download_item_view.h
@@ -197,7 +197,6 @@ class DownloadItemView : public views::ButtonListener,
 
   // Elements of our particular download
   std::wstring status_text_;
-  bool show_status_text_;
 
   // The font used to print the file name and status.
   gfx::Font font_;
diff --git a/chrome/browser/ui/webui/downloads_dom_handler.cc b/chrome/browser/ui/webui/downloads_dom_handler.cc
index 82b12d0..50d816a 100644
--- a/chrome/browser/ui/webui/downloads_dom_handler.cc
+++ b/chrome/browser/ui/webui/downloads_dom_handler.cc
@@ -124,20 +124,12 @@ void DownloadsDOMHandler::ModelChanged() {
                                      &download_items_);
   sort(download_items_.begin(), download_items_.end(), DownloadItemSorter());
 
-  // Scan for any in progress downloads and add ourself to them as an observer.
+  // Add ourself to all download items as an observer.
   for (OrderedDownloads::iterator it = download_items_.begin();
        it != download_items_.end(); ++it) {
     if (static_cast<int>(it - download_items_.begin()) > kMaxDownloads)
       break;
-
-    DownloadItem* download = *it;
-    if (download->IsInProgress()) {
-      // We want to know what happens as the download progresses.
-      download->AddObserver(this);
-    } else if (download->safety_state() == DownloadItem::DANGEROUS) {
-      // We need to be notified when the user validates the dangerous download.
-      download->AddObserver(this);
-    }
+    (*it)->AddObserver(this);
   }
 
   SendCurrentDownloads();
@@ -151,6 +143,8 @@ void DownloadsDOMHandler::HandleGetDownloads(const ListValue* args) {
   } else {
     SendCurrentDownloads();
   }
+
+  download_manager_->CheckForHistoryFilesRemoval();
 }
 
 void DownloadsDOMHandler::HandleOpenFile(const ListValue* args) {
diff --git a/chrome/browser/ui/webui/downloads_ui.cc b/chrome/browser/ui/webui/downloads_ui.cc
index e53c15d..3c67c71 100644
--- a/chrome/browser/ui/webui/downloads_ui.cc
+++ b/chrome/browser/ui/webui/downloads_ui.cc
@@ -63,6 +63,7 @@ DownloadsUIHTMLSource::DownloadsUIHTMLSource()
 
   // Status.
   AddLocalizedString("status_cancelled", IDS_DOWNLOAD_TAB_CANCELED);
+  AddLocalizedString("status_removed", IDS_DOWNLOAD_FILE_REMOVED);
   AddLocalizedString("status_paused", IDS_DOWNLOAD_PROGRESS_PAUSED);
   AddLocalizedString("status_interrupted", IDS_DOWNLOAD_PROGRESS_INTERRUPTED);