Cleanup usage of history namespace in components/history

chrome/browser/ui/webui/ntp/most_visited_handler.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_WEBUI_NTP_MOST_VISITED_HANDLER_H_
 #define CHROME_BROWSER_UI_WEBUI_NTP_MOST_VISITED_HANDLER_H_
 
 #include <string>
 #include <vector>
 
 #include "base/memory/weak_ptr.h"
 #include "base/scoped_observer.h"
 #include "components/history/core/browser/history_types.h"
 #include "components/history/core/browser/top_sites_observer.h"
 #include "content/public/browser/web_ui_message_handler.h"
 
 class GURL;
-class PageUsageData;
 
 namespace base {
 class ListValue;
 class Value;
 }
 
 namespace user_prefs {
 class PrefRegistrySyncable;
 }
 
@@ skipping 83 matching lines @@
   // Whether the user has performed a "tracked" action to leave the page or not.
   bool user_action_logged_;
 
   // For callbacks which may be run after destruction.
   base::WeakPtrFactory<MostVisitedHandler> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(MostVisitedHandler);
 };
 
 #endif  // CHROME_BROWSER_UI_WEBUI_NTP_MOST_VISITED_HANDLER_H_