Cleanup: Remove unneeded forward declarations from chrome/browser/ui/webui.

chrome/browser/ui/webui/sync_promo_handler.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_UI_WEBUI_SYNC_PROMO_HANDLER_H_
 #define CHROME_BROWSER_UI_WEBUI_SYNC_PROMO_HANDLER_H_
 #pragma once
 
 #include "chrome/browser/ui/webui/sync_setup_handler.h"
 
+class PrefService;
+
 // The handler for Javascript messages related to the "sync promo" page.
 class SyncPromoHandler : public SyncSetupHandler {
  public:
   explicit SyncPromoHandler(ProfileManager* profile_manager);
   virtual ~SyncPromoHandler();
 
   // Called to register our preferences before we use them (so there will be a
   // default if not present yet).
   static void RegisterUserPrefs(PrefService* prefs);
 
@@ skipping 47 matching lines @@
 
   // If the user closes the whole window we'll get a close notification from the
   // tab as well, so this bool acts as a small mutex to only report the close
   // method once.
   bool window_already_closed_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncPromoHandler);
 };
 
 #endif  // CHROME_BROWSER_UI_WEBUI_SYNC_PROMO_HANDLER_H_