Make PrerenderHandle an observer of PrerenderContents.

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_
 
 #include <map>
 
 #include "base/compiler_specific.h"
@@ skipping 13 matching lines @@
                             public WebKit::WebPrerenderingSupport {
  public:
   PrerenderDispatcher();
   virtual ~PrerenderDispatcher();
 
   bool IsPrerenderURL(const GURL& url) const;
 
  private:
   friend class PrerenderDispatcherTest;
 
-  void OnAddPrerenderURL(const GURL& url);
-  void OnRemovePrerenderURL(const GURL& url);
+  // Message handlers for messages from the browser process.
+  void OnPrerenderStart(int prerender_id);
+  void OnPrerenderAddAlias(int prerender_id, const GURL& url);
+  void OnPrerenderStop(int prerender_id);
 
   // From RenderProcessObserver:
   virtual bool OnControlMessageReceived(const IPC::Message& message) OVERRIDE;
 
   // From WebPrerenderingSupport:
   virtual void add(const WebKit::WebPrerender& prerender) OVERRIDE;
   virtual void cancel(const WebKit::WebPrerender& prerender) OVERRIDE;
   virtual void abandon(const WebKit::WebPrerender& prerender) OVERRIDE;
 
-  typedef std::map<GURL, int> PrerenderMap;
-  PrerenderMap prerender_urls_;
+  // From WebKit, prerender elements launched by renderers in our process.
+  // TODO(gavinp): Store a WebKit::WebPrerender* here once the WebKit API
+  // updates to allow this.
+  std::map<int, GURL> prerenders_;
+
+  // From the browser process, which prerenders are running, indexed by URL.
+  // Updated by the browser processes as aliases are discovered.
+  std::multimap<GURL, int> running_prerender_urls_;
 };
 
 }  // namespace prerender
 
 #endif  // CHROME_RENDERER_PRERENDER_PRERENDER_DISPATCHER_H_