Cleanup: Remove unneeded forward declarations from chrome/browser/extensions.

chrome/browser/extensions/extension_service.h

 // Copyright (c) 2011 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_SERVICE_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_SERVICE_H_
 #pragma once
 
+#include <list>
 #include <map>
 #include <set>
 #include <string>
 #include <vector>
 
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
 #include "base/file_path.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/linked_ptr.h"
@@ skipping 27 matching lines @@
 
 class AppNotificationManager;
 class BookmarkExtensionEventRouter;
 class CrxInstaller;
 class ExtensionBrowserEventRouter;
 class ExtensionContentSettingsStore;
 class ExtensionCookiesEventRouter;
 class ExtensionDownloadsEventRouter;
 class ExtensionFileBrowserEventRouter;
 class ExtensionGlobalError;
-class ExtensionInstallUI;
 class ExtensionManagementEventRouter;
 class ExtensionPreferenceEventRouter;
 class ExtensionSyncData;
 class ExtensionToolbarModel;
 class ExtensionUpdater;
 class ExtensionWebNavigationEventRouter;
 class HistoryExtensionEventRouter;
 class GURL;
 class PendingExtensionManager;
 class Profile;
@@ skipping 727 matching lines @@
   extensions::ProcessMap process_map_;
 
   FRIEND_TEST_ALL_PREFIXES(ExtensionServiceTest,
                            InstallAppsWithUnlimtedStorage);
   FRIEND_TEST_ALL_PREFIXES(ExtensionServiceTest,
                            InstallAppsAndCheckStorageProtection);
   DISALLOW_COPY_AND_ASSIGN(ExtensionService);
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_SERVICE_H_