Safely cancel prerenders on threads other than the UI thread

chrome/browser/prerender/prerender_manager.h

 // Copyright (c) 2011 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_BROWSER_PRERENDER_PRERENDER_MANAGER_H_
 #define CHROME_BROWSER_PRERENDER_PRERENDER_MANAGER_H_
 #pragma once
 
 #include <list>
 #include <map>
@@ skipping 30 matching lines @@
 // Adds either a preload or a pending preload to the PrerenderManager.
 // Must be called on the UI thread.
 void HandlePrefetchTag(
     const base::WeakPtr<PrerenderManager>& prerender_manager,
     int render_process_id,
     int render_view_id,
     const GURL& url,
     const GURL& referrer,
     bool make_pending);
 
-// Given a renderer process id and view id, this will destroy any preloads and
-// pending preloads than are using or originated in the given render view.
-// Must be called on the UI thread.
-void DestroyPreloadForRenderView(
-    const base::WeakPtr<PrerenderManager>& prerender_manager_weak_ptr,
-    int render_process_id,
-    int render_view_id,
-    FinalStatus final_status);
-
 // PrerenderManager is responsible for initiating and keeping prerendered
 // views of webpages. All methods must be called on the UI thread unless
 // indicated otherwise.
 class PrerenderManager : public base::SupportsWeakPtr<PrerenderManager>,
                          public base::NonThreadSafe {
  public:
   // PrerenderManagerMode is used in a UMA_HISTOGRAM, so please do not
   // add in the middle.
   enum PrerenderManagerMode {
     PRERENDER_MODE_DISABLED,
@@ skipping 16 matching lines @@
       const std::pair<int, int>& child_route_id_pair,
       const GURL& url,
       const GURL& referrer);
 
   void AddPendingPreload(const std::pair<int, int>& child_route_id_pair,
                          const GURL& url,
                          const GURL& referrer);
 
   // Destroy all preloads for the given child route id pair and assign a final
   // status to them.
-  void DestroyPreloadForChildRouteIdPair(
+  virtual void DestroyPreloadForChildRouteIdPair(
       const std::pair<int, int>& child_route_id_pair,
       FinalStatus final_status);
 
   // For a given TabContents that wants to navigate to the URL supplied,
   // determines whether a preloaded version of the URL can be used,
   // and substitutes the prerendered RVH into the TabContents.  Returns
   // whether or not a prerendered RVH could be used or not.
   bool MaybeUsePreloadedPage(TabContents* tab_contents, const GURL& url);
   bool MaybeUsePreloadedPageOld(TabContents* tab_contents, const GURL& url);
 
@@ skipping 202 matching lines @@
 
   // Cancels pending tasks on deletion.
   ScopedRunnableMethodFactory<PrerenderManager> runnable_method_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PrerenderManager);
 };
 
 }  // namespace prerender
 
 #endif  // CHROME_BROWSER_PRERENDER_PRERENDER_MANAGER_H_