content: Cleanup class/struct forward declarations

content/public/browser/web_ui_controller.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 CONTENT_PUBLIC_BROWSER_WEB_UI_CONTROLLER_H_
 #define CONTENT_PUBLIC_BROWSER_WEB_UI_CONTROLLER_H_
 
 #include "base/strings/string16.h"
 #include "content/common/content_export.h"
 
 class GURL;
 
 namespace base {
 class ListValue;
 }
 
 namespace content {
 
 class RenderFrameHost;
-class RenderViewHost;
 class WebUI;
 
 // A WebUI page is controller by the embedder's WebUIController object. It
 // manages the data source and message handlers.
 class CONTENT_EXPORT WebUIController {
  public:
   explicit WebUIController(WebUI* web_ui) : web_ui_(web_ui) {}
   virtual ~WebUIController() {}
 
   // Allows the controller to override handling all messages from the page.
   // Return true if the message handling was overridden.
   virtual bool OverrideHandleWebUIMessage(const GURL& source_url,
                                           const std::string& message,
                                           const base::ListValue& args);
 
   // Called when a RenderFrame is created.  This is *not* called for every
   // page load because in some cases a RenderFrame will be reused, for example
   // when reloading or navigating to a same-site URL.
   virtual void RenderFrameCreated(RenderFrameHost* render_frame_host) {}
 
   WebUI* web_ui() const { return web_ui_; }
 
  private:
   WebUI* web_ui_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_WEB_UI_CONTROLLER_H_