chrome: Cleanup class/struct forward declarations

chrome/browser/extensions/api/gcm/gcm_api.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_EXTENSIONS_API_GCM_GCM_API_H_
 #define CHROME_BROWSER_EXTENSIONS_API_GCM_GCM_API_H_
 
 #include "chrome/common/extensions/api/gcm.h"
 #include "components/gcm_driver/gcm_client.h"
 #include "extensions/browser/extension_function.h"
 
 namespace gcm {
 class GCMDriver;
-class GCMProfileService;
 }  // namespace gcm
 
 class Profile;
 
 namespace extensions {
 
 class GcmApiFunction : public AsyncExtensionFunction {
  public:
   GcmApiFunction() {}
 
@@ skipping 80 matching lines @@
 
  private:
   // The application we route the event to is running in context of the
   // |profile_| and the latter outlives the event router.
   Profile* profile_;
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_GCM_GCM_API_H_