Abandon prerenders upon render thread shutdown.

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 <memory>
 #include <set>
@@ skipping 31 matching lines @@
   void OnPrerenderRemoveAliases(const std::vector<GURL>& aliases);
   void OnPrerenderStop(int prerender_id);
 
   // From RenderProcessObserver:
   bool OnControlMessageReceived(const IPC::Message& message) override;
 
   // From WebPrerenderingSupport:
   void add(const blink::WebPrerender& prerender) override;
   void cancel(const blink::WebPrerender& prerender) override;
   void abandon(const blink::WebPrerender& prerender) override;
+  void detachRenderer() override;
 
   // From WebKit, prerender elements launched by renderers in our process.
   std::map<int, blink::WebPrerender> prerenders_;
 
   // From the browser process, which prerenders are running, indexed by URL.
   // Updated by the browser processes as aliases are discovered.
   std::multiset<GURL> running_prerender_urls_;
 };
 
 }  // namespace prerender
 
 #endif  // CHROME_RENDERER_PRERENDER_PRERENDER_DISPATCHER_H_