Adding unit tests for PrerenderDispatcher.

chrome/renderer/prerender/prerender_dispatcher.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_PRERENDER_PRERENDER_DISPATCHER_H_
 #define CHROME_RENDERER_PRERENDER_PRERENDER_DISPATCHER_H_
 #pragma once
 
 #include <map>
 
@@ skipping 13 matching lines @@
 // it holds on to other objects that must exist once per-renderer process,
 // such as the PrerenderingSupport.
 class PrerenderDispatcher : public content::RenderProcessObserver {
  public:
   PrerenderDispatcher();
   virtual ~PrerenderDispatcher();
 
   bool IsPrerenderURL(const GURL & url) const;
 
  private:
+  friend class PrerenderDispatcherTest;
+
   void OnAddPrerenderURL(const GURL& url);
   void OnRemovePrerenderURL(const GURL& url);
 
   // RenderProcessObserver:
   virtual bool OnControlMessageReceived(const IPC::Message& message) OVERRIDE;
 
   typedef std::map<GURL, int> PrerenderMap;
   PrerenderMap prerender_urls_;
 
   // There is one PrerenderingSupport object per renderer, and it provides
   // the interface to prerendering to the WebKit platform.
   scoped_ptr<PrerenderingSupport> prerendering_support_;
 };
 
 }  // namespace prerender
 
 #endif  // CHROME_RENDERER_PRERENDER_PRERENDER_DISPATCHER_H_