Move Extension into extensions namespace

chrome/renderer/chrome_content_renderer_client.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_RENDERER_CHROME_CONTENT_RENDERER_CLIENT_H_
 #define CHROME_RENDERER_CHROME_CONTENT_RENDERER_CLIENT_H_
 #pragma once
 
 #include <set>
 #include <string>
 
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/string16.h"
 #include "content/public/renderer/content_renderer_client.h"
 
 class ChromeRenderProcessObserver;
-class Extension;
 class ExtensionDispatcher;
 class ExtensionSet;
 class RendererHistogramSnapshots;
 class RendererNetPredictor;
 class SpellCheck;
 class SpellCheckProvider;
 class VisitedLinkSlave;
 
 struct ChromeViewHostMsg_GetPluginInfo_Status;
 
@@ skipping 136 matching lines @@
   scoped_ptr<RendererNetPredictor> net_predictor_;
   scoped_ptr<SpellCheck> spellcheck_;
   scoped_ptr<VisitedLinkSlave> visited_link_slave_;
   scoped_ptr<safe_browsing::PhishingClassifierFilter> phishing_classifier_;
   scoped_ptr<prerender::PrerenderDispatcher> prerender_dispatcher_;
 };
 
 }  // namespace chrome
 
 #endif  // CHROME_RENDERER_CHROME_CONTENT_RENDERER_CLIENT_H_