Revert 142427 - Cleaning Up Extensions When Local Content Removed

Reverted because unpacked extensions appear to unintentionally get removed: crbug.com/133381.

This fixes an issue where removing an extension's local content, e.g. deleting
the user-data-dir/Default/Extensions/<id> directory, would result in a broken
extension. Chrome will now uninstall/remove any extensions where the path to
the extension cannot be resolved.

BUG=31910
TEST=ExtensionServiceTest.CleanupInternalExtensionsMissingLocalContent;
ExtensionServiceTest.CleanupUnpackedExtensionsMissingLocalContent;
test by hand by loading an extension, deleting the local directory, and
restarting chrome


Review URL: https://chromiumcodereview.appspot.com/10541126

TBR=rdevlin.cronin@chromium.org
Review URL: https://chromiumcodereview.appspot.com/10581021

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@143012 0039d316-1c4b-4281-b951-d872f2087c98

13 files changed, 157 insertions, 430 deletions

diff --git a/chrome/browser/extensions/extension_garbage_collector.cc b/chrome/browser/extensions/extension_garbage_collector.cc
deleted file mode 100644
index 933f25c..0000000
--- a/chrome/browser/extensions/extension_garbage_collector.cc
+++ /dev/null
@@ -1,192 +0,0 @@
-// Copyright (c) 2012 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 "chrome/browser/extensions/extension_garbage_collector.h"
-
-#include <map>
-#include <string>
-
-#include "base/bind.h"
-#include "base/file_util.h"
-#include "base/logging.h"
-#include "chrome/browser/extensions/extension_prefs.h"
-#include "chrome/browser/extensions/extension_service.h"
-#include "chrome/browser/prefs/pref_service.h"
-#include "chrome/common/extensions/extension_file_util.h"
-#include "content/public/browser/browser_thread.h"
-
-namespace extensions {
-
-ExtensionGarbageCollector::ExtensionGarbageCollector(
-    ExtensionService* extension_service)
-    : extension_service_(extension_service) {
-}
-
-ExtensionGarbageCollector::~ExtensionGarbageCollector() {
-}
-
-void ExtensionGarbageCollector::GarbageCollectExtensions() {
-  CHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
-
-  FilePath install_directory = extension_service_->install_directory();
-
-  // NOTE: It's important to use the file thread here because when the
-  // ExtensionService installs an extension, it begins on the file thread, and
-  // there are ordering dependencies between all of the extension-file-
-  // management tasks. If we do not follow the same thread pattern as the
-  // ExtensionService, then a race condition develops.
-  content::BrowserThread::PostTask(
-      content::BrowserThread::FILE, FROM_HERE,
-      base::Bind(
-           &ExtensionGarbageCollector::
-               CheckExtensionDirectoriesOnBackgroundThread,
-           base::Unretained(this),
-           install_directory));
-}
-
-void ExtensionGarbageCollector::CheckExtensionDirectoriesOnBackgroundThread(
-    const FilePath& install_directory) {
-  CHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::FILE));
-
-  DVLOG(1) << "Garbage collecting extensions...";
-
-  if (!file_util::DirectoryExists(install_directory))
-    return;
-
-  std::set<FilePath> extension_paths;
-
-  file_util::FileEnumerator enumerator(install_directory,
-                                       false,  // Not recursive.
-                                       file_util::FileEnumerator::DIRECTORIES);
-
-  for (FilePath extension_path = enumerator.Next(); !extension_path.empty();
-       extension_path = enumerator.Next()) {
-    std::string extension_id = extension_path.BaseName().MaybeAsASCII();
-    if (!Extension::IdIsValid(extension_id))
-      extension_id.clear();
-
-    // Delete directories that aren't valid IDs.
-    if (extension_id.empty()) {
-      DVLOG(1) << "Deleting invalid extension directory "
-               << extension_path.value() << ".";
-      file_util::Delete(extension_path, true);  // Recursive.
-      continue;
-    }
-
-    extension_paths.insert(extension_path);
-  }
-
-  content::BrowserThread::PostTask(
-      content::BrowserThread::UI, FROM_HERE,
-      base::Bind(
-           &ExtensionGarbageCollector::CheckExtensionPreferences,
-           base::Unretained(this),
-           extension_paths));
-}
-
-void ExtensionGarbageCollector::CheckExtensionPreferences(
-    const std::set<FilePath>& extension_paths) {
-  CHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
-
-  ExtensionPrefs* extension_prefs = extension_service_->extension_prefs();
-
-  if (extension_prefs->pref_service()->ReadOnly())
-    return;
-
-  scoped_ptr<ExtensionPrefs::ExtensionsInfo> info(
-      extension_prefs->GetInstalledExtensionsInfo());
-
-  std::map<std::string, FilePath> extension_pref_paths;
-  for (size_t i = 0; i < info->size(); ++i) {
-    extension_pref_paths[info->at(i)->extension_id] =
-        info->at(i)->extension_path;
-  }
-
-  std::set<std::string> extension_ids;
-
-  // Check each directory for a reference in the preferences.
-  for (std::set<FilePath>::const_iterator path = extension_paths.begin();
-       path != extension_paths.end();
-       ++path) {
-    std::string extension_id;
-    extension_id = path->BaseName().MaybeAsASCII();
-    if (extension_id.empty())
-      continue;
-
-    extension_ids.insert(extension_id);
-
-    std::map<std::string, FilePath>::const_iterator iter =
-        extension_pref_paths.find(extension_id);
-
-    if (iter == extension_pref_paths.end()) {
-      DVLOG(1) << "Deleting unreferenced install for directory "
-               << path->LossyDisplayName() << ".";
-      content::BrowserThread::PostTask(
-          content::BrowserThread::FILE, FROM_HERE,
-          base::Bind(
-              &extension_file_util::DeleteFile,
-              *path,
-              true));  // recursive.
-      continue;
-    }
-
-    // Clean up old version directories.
-    content::BrowserThread::PostTask(
-        content::BrowserThread::FILE, FROM_HERE,
-        base::Bind(
-             &ExtensionGarbageCollector::CleanupOldVersionsOnBackgroundThread,
-             base::Unretained(this), *path, iter->second.BaseName()));
-  }
-
-  // Check each entry in the preferences for an existing path.
-  for (std::map<std::string, FilePath>::const_iterator extension =
-           extension_pref_paths.begin();
-       extension != extension_pref_paths.end();
-       ++extension) {
-    std::set<std::string>::const_iterator iter = extension_ids.find(
-        extension->first);
-
-    if (iter != extension_ids.end())
-      continue;
-
-    std::string extension_id = extension->first;
-
-    DVLOG(1) << "Could not access local content for extension with id "
-             << extension_id << "; uninstalling extension.";
-
-    // If the extension failed to load fully (e.g. the user deleted an unpacked
-    // extension's manifest or the manifest points to the wrong path), we cannot
-    // use UninstallExtension, which relies on a valid Extension object.
-    if (!extension_service_->GetInstalledExtension(extension_id)) {
-      scoped_ptr<ExtensionInfo> info(extension_service_->extension_prefs()
-          ->GetInstalledExtensionInfo(extension_id));
-      extension_service_->extension_prefs()->OnExtensionUninstalled(
-          extension_id, info->extension_location, false);
-    } else {
-      extension_service_->UninstallExtension(extension_id, false, NULL);
-    }
-  }
-}
-
-void ExtensionGarbageCollector::CleanupOldVersionsOnBackgroundThread(
-    const FilePath& path,
-    const FilePath& current_version) {
-  CHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::FILE));
-  file_util::FileEnumerator versions_enumerator(
-      path,
-      false,  // Not recursive.
-      file_util::FileEnumerator::DIRECTORIES);
-  for (FilePath version_dir = versions_enumerator.Next();
-       !version_dir.value().empty();
-       version_dir = versions_enumerator.Next()) {
-    if (version_dir.BaseName() != current_version) {
-      DVLOG(1) << "Deleting old version for directory "
-               << version_dir.LossyDisplayName() << ".";
-      if (!file_util::Delete(version_dir, true))  // Recursive.
-        NOTREACHED();
-    }
-  }
-}
-
-}  // namespace extensions
diff --git a/chrome/browser/extensions/extension_garbage_collector.h b/chrome/browser/extensions/extension_garbage_collector.h
deleted file mode 100644
index bf75b1a..0000000
--- a/chrome/browser/extensions/extension_garbage_collector.h
+++ /dev/null
@@ -1,53 +0,0 @@
-// Copyright (c) 2012 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_EXTENSIONS_EXTENSION_GARBAGE_COLLECTOR_H_
-#define CHROME_BROWSER_EXTENSIONS_EXTENSION_GARBAGE_COLLECTOR_H_
-#pragma once
-
-#include <set>
-
-#include "base/file_path.h"
-
-class ExtensionService;
-
-// Garbage collection for extensions. This will delete any directories in the
-// installation directory of |extension_service_| that aren't valid, as well
-// as removing any references in the preferences to extensions that are
-// missing local content.
-namespace extensions {
-
-class ExtensionGarbageCollector {
- public:
-  explicit ExtensionGarbageCollector(ExtensionService* extension_service);
-  virtual ~ExtensionGarbageCollector();
-
-  // Begin garbage collection; fetch the installed extensions' ids.
-  void GarbageCollectExtensions();
-
- private:
-  // Check the installation directory for directories with invalid extension
-  // ids, deleting them if found. Call CheckExtensionPreferences with a list of
-  // present directories.
-  void CheckExtensionDirectoriesOnBackgroundThread(
-      const FilePath& installation_directory);
-
-  // Check for any extension directories which:
-  //   - Are an old version of a current extension;
-  //   - Are present in the preferences but not on the file system;
-  //   - Are present on the file system, but not in the preferences
-  // and delete them if found.
-  void CheckExtensionPreferences(const std::set<FilePath>& extension_paths);
-
-  // Helper function to cleanup any old versions of an extension in the
-  // extension's base directory.
-  void CleanupOldVersionsOnBackgroundThread(
-      const FilePath& path, const FilePath& current_version);
-
-  ExtensionService* extension_service_;
-};
-
-}  // namespace extensions
-
-#endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_GARBAGE_COLLECTOR_H_
diff --git a/chrome/browser/extensions/extension_service.cc b/chrome/browser/extensions/extension_service.cc
index 710643b..f4063bc 100644
--- a/chrome/browser/extensions/extension_service.cc
+++ b/chrome/browser/extensions/extension_service.cc
@@ -119,6 +119,7 @@
 #include "chrome/browser/chromeos/extensions/input_method_event_router.h"
 #include "chrome/browser/chromeos/extensions/media_player_event_router.h"
 #include "chrome/browser/chromeos/input_method/input_method_manager.h"
+#include "chrome/browser/extensions/extension_input_ime_api.h"
 #include "webkit/fileapi/file_system_context.h"
 #include "webkit/fileapi/file_system_mount_point_provider.h"
 #endif
@@ -324,8 +325,6 @@ ExtensionService::ExtensionService(Profile* profile,
     : profile_(profile),
       system_(ExtensionSystem::Get(profile)),
       extension_prefs_(extension_prefs),
-      extension_garbage_collector_(
-          new extensions::ExtensionGarbageCollector(this)),
       settings_frontend_(extensions::SettingsFrontend::Create(profile)),
       pending_extension_manager_(*ALLOW_THIS_IN_INITIALIZER_LIST(this)),
       install_directory_(install_directory),
@@ -1847,7 +1846,23 @@ void ExtensionService::ReloadExtensions() {
 }
 
 void ExtensionService::GarbageCollectExtensions() {
-  extension_garbage_collector_->GarbageCollectExtensions();
+  if (extension_prefs_->pref_service()->ReadOnly())
+    return;
+
+  scoped_ptr<ExtensionPrefs::ExtensionsInfo> info(
+      extension_prefs_->GetInstalledExtensionsInfo());
+
+  std::map<std::string, FilePath> extension_paths;
+  for (size_t i = 0; i < info->size(); ++i)
+    extension_paths[info->at(i)->extension_id] = info->at(i)->extension_path;
+
+  if (!BrowserThread::PostTask(
+          BrowserThread::FILE, FROM_HERE,
+          base::Bind(
+              &extension_file_util::GarbageCollectExtensions,
+              install_directory_,
+              extension_paths)))
+    NOTREACHED();
 
   // Also garbage-collect themes.  We check |profile_| to be
   // defensive; in the future, we may call GarbageCollectExtensions()
@@ -2013,7 +2028,7 @@ void ExtensionService::InitializePermissions(const Extension* extension) {
     // Other than for unpacked extensions, CrxInstaller should have guaranteed
     // that we aren't downgrading.
     if (extension->location() != Extension::LOAD)
-      CHECK_GE(extension->version()->CompareTo(*(old->version())), 0);
+      CHECK(extension->version()->CompareTo(*(old->version())) >= 0);
 
     // Extensions get upgraded if the privileges are allowed to increase or
     // the privileges haven't increased.
diff --git a/chrome/browser/extensions/extension_service.h b/chrome/browser/extensions/extension_service.h
index f46ed87..b79ed33 100644
--- a/chrome/browser/extensions/extension_service.h
+++ b/chrome/browser/extensions/extension_service.h
@@ -27,7 +27,6 @@
 #include "chrome/browser/extensions/app_shortcut_manager.h"
 #include "chrome/browser/extensions/app_sync_bundle.h"
 #include "chrome/browser/extensions/apps_promo.h"
-#include "chrome/browser/extensions/extension_garbage_collector.h"
 #include "chrome/browser/extensions/extension_icon_manager.h"
 #include "chrome/browser/extensions/extension_menu_manager.h"
 #include "chrome/browser/extensions/extension_prefs.h"
@@ -712,11 +711,6 @@ class ExtensionService
   // Preferences for the owning profile (weak reference).
   ExtensionPrefs* extension_prefs_;
 
-  // The ExtensionGarbageCollector associated with this service; this is
-  // responsible for cleaning up old or partially deleted extensions.
-  scoped_ptr<extensions::ExtensionGarbageCollector>
-      extension_garbage_collector_;
-
   // Settings for the owning profile.
   scoped_ptr<extensions::SettingsFrontend> settings_frontend_;
 
diff --git a/chrome/browser/extensions/extension_service_unittest.cc b/chrome/browser/extensions/extension_service_unittest.cc
index c657c10..c23230a 100644
--- a/chrome/browser/extensions/extension_service_unittest.cc
+++ b/chrome/browser/extensions/extension_service_unittest.cc
@@ -235,6 +235,7 @@ class MockExtensionProvider : public ExternalExtensionProviderInterface {
 class MockProviderVisitor
     : public ExternalExtensionProviderInterface::VisitorInterface {
  public:
+
   // The provider will return |fake_base_path| from
   // GetBaseCrxFilePath().  User can test the behavior with
   // and without an empty path using this parameter.
@@ -1006,6 +1007,7 @@ void PackExtensionTestClient::OnPackFailure(const std::string& error_message,
      FAIL() << "Packing should not fail.";
   else
      FAIL() << "Existing CRX should have been overwritten.";
+
 }
 
 // Test loading good extensions from the profile directory.
@@ -1149,46 +1151,9 @@ TEST_F(ExtensionServiceTest, LoadAllExtensionsFromDirectoryFail) {
       UTF16ToUTF8(GetErrors()[3]);
 };
 
-// Test that old versions of extensions are deleted during garbage collection.
-TEST_F(ExtensionServiceTest, GarbageCollectOldVersions) {
-  PluginService::GetInstance()->Init();
-
-  FilePath source_install_dir = data_dir_
-      .AppendASCII("garbage_collection")
-      .AppendASCII("Extensions");
-
-  FilePath pref_path = source_install_dir
-      .DirName()
-      .AppendASCII("Preferences");
-
-  InitializeInstalledExtensionService(pref_path, source_install_dir);
-
-  // Verify that there are two versions present initially.
-  ASSERT_TRUE(file_util::PathExists(
-      extensions_install_dir_.AppendASCII("fdoajpacpdeapbmhbblepcnilfkpmkff")
-                             .AppendASCII("1.0_0")));
-  ASSERT_TRUE(file_util::PathExists(
-      extensions_install_dir_.AppendASCII("fdoajpacpdeapbmhbblepcnilfkpmkff")
-                             .AppendASCII("1.1_0")));
-
-  ValidatePrefKeyCount(1u);
-
-  service_->Init();
-  loop_.RunAllPending();
-
-  // Garbage collection should have deleted the old version.
-  ASSERT_FALSE(file_util::PathExists(
-      extensions_install_dir_.AppendASCII("fdoajpacpdeapbmhbblepcnilfkpmkff")
-                             .AppendASCII("1.0_0")));
-  ASSERT_TRUE(file_util::PathExists(
-      extensions_install_dir_.AppendASCII("fdoajpacpdeapbmhbblepcnilfkpmkff")
-                             .AppendASCII("1.1_0")));
-}
-
-// Test that extensions which were deleted from the preferences are cleaned up
-// during startup.
+// Test that partially deleted extensions are cleaned up during startup
 // Test loading bad extensions from the profile directory.
-TEST_F(ExtensionServiceTest, GarbageCollectOnStartup) {
+TEST_F(ExtensionServiceTest, CleanupOnStartup) {
   PluginService::GetInstance()->Init();
 
   FilePath source_install_dir = data_dir_
@@ -1200,13 +1165,11 @@ TEST_F(ExtensionServiceTest, GarbageCollectOnStartup) {
 
   InitializeInstalledExtensionService(pref_path, source_install_dir);
 
-  ValidatePrefKeyCount(3u);
-
   // Simulate that one of them got partially deleted by clearing its pref.
   {
     DictionaryPrefUpdate update(profile_->GetPrefs(), "extensions.settings");
     DictionaryValue* dict = update.Get();
-    ASSERT_TRUE(dict);
+    ASSERT_TRUE(dict != NULL);
     dict->Remove("behllobkkfkfnphdnhnkndlbkcpglgmj", NULL);
   }
 
@@ -1229,93 +1192,6 @@ TEST_F(ExtensionServiceTest, GarbageCollectOnStartup) {
   ASSERT_FALSE(file_util::PathExists(extension_dir));
 }
 
-// Test that internal extensions which are referenced in the preferences but
-// had their content deleted are cleaned up during startup.
-TEST_F(ExtensionServiceTest, GarbageCollectInternalExtensionsMissingContent) {
-  PluginService::GetInstance()->Init();
-
-  FilePath source_dir = data_dir_.AppendASCII("good").AppendASCII("Extensions");
-  FilePath pref_path = source_dir.DirName().AppendASCII("Preferences");
-
-  InitializeInstalledExtensionService(pref_path, source_dir);
-
-  ValidatePrefKeyCount(3u);
-
-  // Delete the extension's directory.
-  FilePath extension_dir = extensions_install_dir_
-      .AppendASCII("behllobkkfkfnphdnhnkndlbkcpglgmj");
-  ASSERT_TRUE(file_util::Delete(extension_dir, true));
-
-  // Run GarbageCollectExtensions.
-  service_->Init();
-  loop_.RunAllPending();
-
-  file_util::FileEnumerator dirs(extensions_install_dir_, false,
-                                 file_util::FileEnumerator::DIRECTORIES);
-  size_t count = 0;
-  while (!dirs.Next().empty())
-    count++;
-
-  // We should have only gotten two extensions now.
-  EXPECT_EQ(2u, count);
-
-  const DictionaryValue* dictionary =
-      profile_->GetPrefs()->GetDictionary("extensions.settings");
-  ASSERT_TRUE(dictionary);
-  ASSERT_FALSE(dictionary->HasKey("behllobkkfkfnphdnhnkndlbkcpglgmj"));
-}
-
-// Test that unpacked extensions which are referenced in the preferences but
-// had their content deleted are cleaned up during startup.
-TEST_F(ExtensionServiceTest, GarbageCollectUnpackedExtensionsMissingContent) {
-  InitializeEmptyExtensionService();
-
-  ScopedTempDir temp;
-  ASSERT_TRUE(temp.CreateUniqueTempDir());
-
-  // Write the manifest dynamically, since we have to delete the file anyway.
-  FilePath extension_path = temp.path();
-  FilePath manifest_path = extension_path.Append(Extension::kManifestFilename);
-  ASSERT_FALSE(file_util::PathExists(manifest_path));
-
-  // Construct a simple manifest and install it.
-  DictionaryValue manifest;
-  manifest.SetString("version", "1.0");
-  manifest.SetString("name", "Cleanup Unpacked Extensions Missing Content");
-  manifest.SetInteger("manifest_version", 2);
-
-  JSONFileValueSerializer serializer(manifest_path);
-  ASSERT_TRUE(serializer.Serialize(manifest));
-
-  extensions::UnpackedInstaller::Create(service_)->Load(extension_path);
-  loop_.RunAllPending();
-
-  // Make sure it installed correctly.
-  EXPECT_EQ(0u, GetErrors().size());
-  ASSERT_EQ(1u, loaded_.size());
-  EXPECT_EQ(Extension::LOAD, loaded_[0]->location());
-  EXPECT_EQ(1u, service_->extensions()->size());
-
-  std::string extension_id = loaded_[0]->id();
-
-  // Make sure it is in the preferences at this point.
-  const DictionaryValue* initial_dictionary =
-      profile_->GetPrefs()->GetDictionary("extensions.settings");
-  ASSERT_TRUE(initial_dictionary);
-  ASSERT_TRUE(initial_dictionary->HasKey(extension_id));
-
-  // Delete local content, GarbageCollectExtensions, and test whether the key
-  // is still in the preferences.
-  ASSERT_TRUE(file_util::Delete(extension_path, true));
-  service_->GarbageCollectExtensions();
-  loop_.RunAllPending();
-
-  const DictionaryValue* final_dictionary =
-      profile_->GetPrefs()->GetDictionary("extensions.settings");
-  ASSERT_TRUE(final_dictionary);
-  ASSERT_FALSE(final_dictionary->HasKey(extension_id));
-}
-
 // Test installing extensions. This test tries to install few extensions using
 // crx files. If you need to change those crx files, feel free to repackage
 // them, throw away the key used and change the id's above.
diff --git a/chrome/browser/sync/test/integration/sync_extension_helper.cc b/chrome/browser/sync/test/integration/sync_extension_helper.cc
index c719aa0..a2151ac 100644
--- a/chrome/browser/sync/test/integration/sync_extension_helper.cc
+++ b/chrome/browser/sync/test/integration/sync_extension_helper.cc
@@ -18,8 +18,6 @@
 #include "chrome/common/string_ordinal.h"
 #include "chrome/browser/sync/test/integration/sync_test.h"
 #include "chrome/browser/sync/test/integration/sync_datatype_helper.h"
-#include "chrome/test/base/ui_test_utils.h"
-#include "content/public/browser/browser_thread.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 using extensions::Extension;
@@ -72,16 +70,6 @@ std::string SyncExtensionHelper::InstallExtension(
     NOTREACHED() << "Could not install extension " << name;
     return "";
   }
-  // extensions::ExtensionGarbageCollector requires that there be a file present
-  // on the file system for all extensions; we mimic this here. This also better
-  // simulates the actual install process.
-  content::BrowserThread::PostTask(
-      content::BrowserThread::FILE, FROM_HERE,
-      base::Bind(
-          base::IgnoreResult(&file_util::CreateDirectory),
-          profile->GetExtensionService()->install_directory()
-              .AppendASCII(extension->id())));
-  ui_test_utils::RunAllPendingInMessageLoop(content::BrowserThread::FILE);
   profile->GetExtensionService()->OnExtensionInstalled(
       extension, extension->UpdatesFromGallery(), StringOrdinal());
   return extension->id();
diff --git a/chrome/chrome_browser_extensions.gypi b/chrome/chrome_browser_extensions.gypi
index a1dea0b..7fa79f3 100644
--- a/chrome/chrome_browser_extensions.gypi
+++ b/chrome/chrome_browser_extensions.gypi
@@ -288,8 +288,6 @@
         'browser/extensions/extension_function_registry.h',
         'browser/extensions/extension_function_util.cc',
         'browser/extensions/extension_function_util.h',
-        'browser/extensions/extension_garbage_collector.cc',
-        'browser/extensions/extension_garbage_collector.h',
         'browser/extensions/extension_global_error.cc',
         'browser/extensions/extension_global_error.h',
         'browser/extensions/extension_global_error_badge.cc',
diff --git a/chrome/common/extensions/extension_file_util.cc b/chrome/common/extensions/extension_file_util.cc
index 8cb95b9..4a6f150 100644
--- a/chrome/common/extensions/extension_file_util.cc
+++ b/chrome/common/extensions/extension_file_util.cc
@@ -419,6 +419,69 @@ bool ValidateExtension(const Extension* extension,
   return true;
 }
 
+void GarbageCollectExtensions(
+    const FilePath& install_directory,
+    const std::map<std::string, FilePath>& extension_paths) {
+  // Nothing to clean up if it doesn't exist.
+  if (!file_util::DirectoryExists(install_directory))
+    return;
+
+  DVLOG(1) << "Garbage collecting extensions...";
+  file_util::FileEnumerator enumerator(install_directory,
+                                       false,  // Not recursive.
+                                       file_util::FileEnumerator::DIRECTORIES);
+  FilePath extension_path;
+  for (extension_path = enumerator.Next(); !extension_path.value().empty();
+       extension_path = enumerator.Next()) {
+    std::string extension_id;
+
+    FilePath basename = extension_path.BaseName();
+    if (IsStringASCII(basename.value())) {
+      extension_id = UTF16ToASCII(basename.LossyDisplayName());
+      if (!Extension::IdIsValid(extension_id))
+        extension_id.clear();
+    }
+
+    // Delete directories that aren't valid IDs.
+    if (extension_id.empty()) {
+      DLOG(WARNING) << "Invalid extension ID encountered in extensions "
+                       "directory: " << basename.value();
+      DVLOG(1) << "Deleting invalid extension directory "
+               << extension_path.value() << ".";
+      file_util::Delete(extension_path, true);  // Recursive.
+      continue;
+    }
+
+    std::map<std::string, FilePath>::const_iterator iter =
+        extension_paths.find(extension_id);
+
+    // If there is no entry in the prefs file, just delete the directory and
+    // move on. This can legitimately happen when an uninstall does not
+    // complete, for example, when a plugin is in use at uninstall time.
+    if (iter == extension_paths.end()) {
+      DVLOG(1) << "Deleting unreferenced install for directory "
+               << extension_path.LossyDisplayName() << ".";
+      file_util::Delete(extension_path, true);  // Recursive.
+      continue;
+    }
+
+    // Clean up old version directories.
+    file_util::FileEnumerator versions_enumerator(
+        extension_path,
+        false,  // Not recursive.
+        file_util::FileEnumerator::DIRECTORIES);
+    for (FilePath version_dir = versions_enumerator.Next();
+         !version_dir.value().empty();
+         version_dir = versions_enumerator.Next()) {
+      if (version_dir.BaseName() != iter->second.BaseName()) {
+        DVLOG(1) << "Deleting old version for directory "
+                 << version_dir.LossyDisplayName() << ".";
+        file_util::Delete(version_dir, true);  // Recursive.
+      }
+    }
+  }
+}
+
 ExtensionMessageBundle* LoadExtensionMessageBundle(
     const FilePath& extension_path,
     const std::string& default_locale,
diff --git a/chrome/common/extensions/extension_file_util.h b/chrome/common/extensions/extension_file_util.h
index 07cd4ec..72a5069 100644
--- a/chrome/common/extensions/extension_file_util.h
+++ b/chrome/common/extensions/extension_file_util.h
@@ -72,6 +72,19 @@ bool ValidateExtension(const extensions::Extension* extension,
 // Returns a list of files that contain private keys inside |extension_dir|.
 std::vector<FilePath> FindPrivateKeyFiles(const FilePath& extension_dir);
 
+// Cleans up the extension install directory. It can end up with garbage in it
+// if extensions can't initially be removed when they are uninstalled (eg if a
+// file is in use).
+//
+// |extensions_dir| is the install directory to look in. |extension_paths| is a
+// map from extension id to full installation path.
+//
+// Obsolete version directories are removed, as are directories that aren't
+// found in |extension_paths|.
+void GarbageCollectExtensions(
+    const FilePath& extensions_dir,
+    const std::map<std::string, FilePath>& extension_paths);
+
 // Loads extension message catalogs and returns message bundle.
 // Returns NULL on error, or if extension is not localized.
 ExtensionMessageBundle* LoadExtensionMessageBundle(
diff --git a/chrome/common/extensions/extension_file_util_unittest.cc b/chrome/common/extensions/extension_file_util_unittest.cc
index 0b3d12b..5551db1 100644
--- a/chrome/common/extensions/extension_file_util_unittest.cc
+++ b/chrome/common/extensions/extension_file_util_unittest.cc
@@ -22,6 +22,63 @@ using extensions::Extension;
 
 namespace keys = extension_manifest_keys;
 
+#if defined(OS_WIN)
+// http://crbug.com/106381
+#define InstallUninstallGarbageCollect DISABLED_InstallUninstallGarbageCollect
+#endif
+TEST(ExtensionFileUtil, InstallUninstallGarbageCollect) {
+  ScopedTempDir temp;
+  ASSERT_TRUE(temp.CreateUniqueTempDir());
+
+  // Create a source extension.
+  std::string extension_id("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa");
+  std::string version("1.0");
+  FilePath src = temp.path().AppendASCII(extension_id);
+  ASSERT_TRUE(file_util::CreateDirectory(src));
+
+  // Create a extensions tree.
+  FilePath all_extensions = temp.path().AppendASCII("extensions");
+  ASSERT_TRUE(file_util::CreateDirectory(all_extensions));
+
+  // Install in empty directory. Should create parent directories as needed.
+  FilePath version_1 = extension_file_util::InstallExtension(src,
+                                                             extension_id,
+                                                             version,
+                                                             all_extensions);
+  ASSERT_EQ(version_1.value(),
+            all_extensions.AppendASCII(extension_id).AppendASCII("1.0_0")
+                .value());
+  ASSERT_TRUE(file_util::DirectoryExists(version_1));
+
+  // Should have moved the source.
+  ASSERT_FALSE(file_util::DirectoryExists(src));
+
+  // Install again. Should create a new one with different name.
+  ASSERT_TRUE(file_util::CreateDirectory(src));
+  FilePath version_2 = extension_file_util::InstallExtension(src,
+                                                             extension_id,
+                                                             version,
+                                                             all_extensions);
+  ASSERT_EQ(version_2.value(),
+            all_extensions.AppendASCII(extension_id).AppendASCII("1.0_1")
+                .value());
+  ASSERT_TRUE(file_util::DirectoryExists(version_2));
+
+  // Collect garbage. Should remove first one.
+  std::map<std::string, FilePath> extension_paths;
+  extension_paths[extension_id] =
+      FilePath().AppendASCII(extension_id).Append(version_2.BaseName());
+  extension_file_util::GarbageCollectExtensions(all_extensions,
+                                                extension_paths);
+  ASSERT_FALSE(file_util::DirectoryExists(version_1));
+  ASSERT_TRUE(file_util::DirectoryExists(version_2));
+
+  // Uninstall. Should remove entire extension subtree.
+  extension_file_util::UninstallExtension(all_extensions, extension_id);
+  ASSERT_FALSE(file_util::DirectoryExists(version_2.DirName()));
+  ASSERT_TRUE(file_util::DirectoryExists(all_extensions));
+}
+
 TEST(ExtensionFileUtil, LoadExtensionWithValidLocales) {
   FilePath install_dir;
   ASSERT_TRUE(PathService::Get(chrome::DIR_TEST_DATA, &install_dir));
diff --git a/chrome/test/data/extensions/garbage_collection/Extensions/fdoajpacpdeapbmhbblepcnilfkpmkff/1.0_0/manifest.json b/chrome/test/data/extensions/garbage_collection/Extensions/fdoajpacpdeapbmhbblepcnilfkpmkff/1.0_0/manifest.json
deleted file mode 100644
index e69d36b..0000000
--- a/chrome/test/data/extensions/garbage_collection/Extensions/fdoajpacpdeapbmhbblepcnilfkpmkff/1.0_0/manifest.json
+++ /dev/null
@@ -1,6 +0,0 @@
-{
-   "description": "An extension to test garbage collection of old versions.",
-   "key": "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC3Yox7PDjjZl7upms+MLnOuswzlX63YH5jVvzug1WoAHVnq/djfHsViG0WgTrxxPiMhuTNqOh2OzdqHRko+xbkBBgpSjV+X1lIvUgZGOx9ImH2pz4kntyRv1z9abuN+rQh+gjglPvLJQuWU6VvjH0zypTaXZiQ4GCojRqD/dWacQIDAQAB",
-   "name": "GarbageCollectOldVersions Extension",
-   "version": "1.0"
-}
diff --git a/chrome/test/data/extensions/garbage_collection/Extensions/fdoajpacpdeapbmhbblepcnilfkpmkff/1.1_0/manifest.json b/chrome/test/data/extensions/garbage_collection/Extensions/fdoajpacpdeapbmhbblepcnilfkpmkff/1.1_0/manifest.json
deleted file mode 100644
index 20a4b3b..0000000
--- a/chrome/test/data/extensions/garbage_collection/Extensions/fdoajpacpdeapbmhbblepcnilfkpmkff/1.1_0/manifest.json
+++ /dev/null
@@ -1,6 +0,0 @@
-{
-   "description": "An extension to test garbage collection of old versions.",
-   "key": "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC3Yox7PDjjZl7upms+MLnOuswzlX63YH5jVvzug1WoAHVnq/djfHsViG0WgTrxxPiMhuTNqOh2OzdqHRko+xbkBBgpSjV+X1lIvUgZGOx9ImH2pz4kntyRv1z9abuN+rQh+gjglPvLJQuWU6VvjH0zypTaXZiQ4GCojRqD/dWacQIDAQAB",
-   "name": "GarbageCollectOldVersions Extension",
-   "version": "1.1"
-}
diff --git a/chrome/test/data/extensions/garbage_collection/Preferences b/chrome/test/data/extensions/garbage_collection/Preferences
deleted file mode 100644
index 92e3b6e..0000000
--- a/chrome/test/data/extensions/garbage_collection/Preferences
+++ /dev/null
@@ -1,20 +0,0 @@
-{
-   "extensions": {
-      "settings": {
-         "fdoajpacpdeapbmhbblepcnilfkpmkff": {
-            "from_bookmark": false,
-            "from_webstore": false,
-            "install_time": "12977681506510306",
-            "location": 1,
-            "manifest": {
-               "description": "An extension to test garbage collection of old versions.",
-               "key": "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC3Yox7PDjjZl7upms+MLnOuswzlX63YH5jVvzug1WoAHVnq/djfHsViG0WgTrxxPiMhuTNqOh2OzdqHRko+xbkBBgpSjV+X1lIvUgZGOx9ImH2pz4kntyRv1z9abuN+rQh+gjglPvLJQuWU6VvjH0zypTaXZiQ4GCojRqD/dWacQIDAQAB",
-               "name": "GarbageCollectOldVersions Extension",
-               "version": "1.1"
-            },
-            "path": "fdoajpacpdeapbmhbblepcnilfkpmkff/1.1_0",
-            "state": 1
-         }
-      }
-   }
-}