chrome: Cleanup class/struct forward declarations

chrome/browser/ui/app_list/app_list_service.h

 // Copyright 2013 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_UI_APP_LIST_APP_LIST_SERVICE_H_
 #define CHROME_BROWSER_UI_APP_LIST_APP_LIST_SERVICE_H_
 
 #include <string>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "ui/gfx/native_widget_types.h"
 
 class AppListControllerDelegate;
 class PrefRegistrySimple;
 class Profile;
 
 namespace base {
 class CommandLine;
 class FilePath;
 }
 
 namespace content {
 struct SpeechRecognitionSessionPreamble;
 }
 
-namespace gfx {
-class ImageSkia;
-}
-
 class AppListService {
  public:
   // Source that triggers the app launcher being enabled. This is used for UMA
   // to track discoverability of the app lancher shortcut after install. Also
   // used to provide custom install behavior (e.g. "always" enable).
   enum AppListEnableSource {
     ENABLE_NOT_RECORDED,        // Indicates app launcher not recently enabled.
     ENABLE_FOR_APP_INSTALL,     // Triggered by a webstore packaged app install.
     ENABLE_VIA_WEBSTORE_LINK,   // Triggered by webstore explicitly via API.
     ENABLE_VIA_COMMAND_LINE,    // Triggered by --enable-app-list.
@@ skipping 88 matching lines @@
   virtual ~AppListService() {}
 
   // Do any once off initialization needed for the app list.
   virtual void Init(Profile* initial_profile) = 0;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(AppListService);
 };
 
 #endif  // CHROME_BROWSER_UI_APP_LIST_APP_LIST_SERVICE_H_