chrome: Cleanup class/struct forward declarations

chrome/browser/ui/toolbar/toolbar_actions_model.h

 // 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_UI_TOOLBAR_TOOLBAR_ACTIONS_MODEL_H_
 #define CHROME_BROWSER_UI_TOOLBAR_TOOLBAR_ACTIONS_MODEL_H_
 
 #include <stddef.h>
 
 #include "base/compiler_specific.h"
@@ skipping 13 matching lines @@
 class Browser;
 class PrefService;
 class Profile;
 class ToolbarActionsBar;
 class ToolbarActionViewController;
 
 namespace extensions {
 class ExtensionActionManager;
 class ExtensionMessageBubbleController;
 class ExtensionRegistry;
-class ExtensionSet;
 }
 
 // Model for the browser actions toolbar. This is a per-profile instance, and
 // manages the user's global preferences.
 // Each browser window will attempt to show browser actions as specified by this
 // model, but if the window is too narrow, actions may end up pushed into the
 // overflow menu on a per-window basis. Callers interested in the arrangement of
 // actions in a particular window should check that window's instance of
 // ToolbarActionsBar, which is responsible for the per-window layout.
 class ToolbarActionsModel
@@ skipping 296 matching lines @@
   // For observing change of toolbar order preference by external entity (sync).
   PrefChangeRegistrar pref_change_registrar_;
   base::Closure pref_change_callback_;
 
   base::WeakPtrFactory<ToolbarActionsModel> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ToolbarActionsModel);
 };
 
 #endif  // CHROME_BROWSER_UI_TOOLBAR_TOOLBAR_ACTIONS_MODEL_H_