Cleanup: Remove some unneeded Extension* class forward declarations.

chrome/browser/extensions/settings_api_bubble_controller.h

-// ::Copyright (c) 2014 The Chromium Authors. All rights reserved.
+// Copyright 2014 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_SETTINGS_API_BUBBLE_CONTROLLER_H_
 #define CHROME_BROWSER_EXTENSIONS_SETTINGS_API_BUBBLE_CONTROLLER_H_
 
 #include <string>
 #include "chrome/browser/extensions/extension_message_bubble_controller.h"
 #include "chrome/common/extensions/manifest_handlers/settings_overrides_handler.h"
 
-class ExtensionService;
-
 namespace extensions {
 
 class SettingsApiBubble;
 
 class SettingsApiBubbleController : public ExtensionMessageBubbleController {
  public:
   SettingsApiBubbleController(Profile* profile, SettingsApiOverrideType type);
   virtual ~SettingsApiBubbleController();
 
   // Whether the controller knows that we should show the bubble for extension
   // with |extension_id|. Returns true if so.
   bool ShouldShow(const std::string& extension_id);
 
   // ExtensionMessageBubbleController:
   virtual bool CloseOnDeactivate() OVERRIDE;
 
  private:
   // A weak pointer to the profile we are associated with. Not owned by us.
   Profile* profile_;
 
   // The type of settings override this bubble will report on.
   SettingsApiOverrideType type_;
 
   DISALLOW_COPY_AND_ASSIGN(SettingsApiBubbleController);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_SETTINGS_API_BUBBLE_CONTROLLER_H_