chrome: Cleanup class/struct forward declarations

chrome/browser/ui/app_list/launcher_page_event_dispatcher.h

 // 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_UI_APP_LIST_LAUNCHER_PAGE_EVENT_DISPATCHER_H_
 #define CHROME_BROWSER_UI_APP_LIST_LAUNCHER_PAGE_EVENT_DISPATCHER_H_
 
 #include <memory>
 #include <string>
 
 #include "base/macros.h"
 #include "extensions/browser/event_router.h"
 #include "extensions/browser/extension_event_histogram_value.h"
 
 class Profile;
 
-namespace base {
-class ListValue;
-}
-
 namespace app_list {
 
 // A class which sends API events to the custom launcher page.
 class LauncherPageEventDispatcher {
  public:
   LauncherPageEventDispatcher(Profile* profile,
                               const std::string& extension_id);
   ~LauncherPageEventDispatcher();
 
   void ProgressChanged(double progress);
   void PopSubpage();
 
  private:
   // Dispatches |event| to |extension_id_|.
   void DispatchEvent(std::unique_ptr<extensions::Event> event);
 
   Profile* profile_;
   std::string extension_id_;
 
   DISALLOW_COPY_AND_ASSIGN(LauncherPageEventDispatcher);
 };
 
 }  // namespace app_list
 
 #endif  // CHROME_BROWSER_UI_APP_LIST_LAUNCHER_PAGE_EVENT_DISPATCHER_H_