Add UMA counter for hung renderers on cross-site navigation.

content/browser/renderer_host/resource_dispatcher_host_impl.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.
 
 // This is the browser side of the resource dispatcher, it receives requests
 // from the child process (i.e. [Renderer, Plugin, Worker]ProcessHost), and
 // dispatches them to URLRequests. It then forwards the messages from the
 // URLRequests back to the correct process for handling.
 //
 // See http://dev.chromium.org/developers/design-documents/multi-process-resource-loading
@@ skipping 137 matching lines @@
     return download_file_manager_;
   }
 
   SaveFileManager* save_file_manager() const {
     return save_file_manager_;
   }
 
   // Called when the unload handler for a cross-site request has finished.
   void OnSwapOutACK(const ViewMsg_SwapOut_Params& params);
 
+  // Called when we want to simulate the renderer process sending
+  // ViewHostMsg_SwapOut_ACK in cases where the renderer has died or is
+  // unresponsive.
+  void OnSimulateSwapOutACK(const ViewMsg_SwapOut_Params& params);
+
   // Called when the renderer loads a resource from its internal cache.
   void OnDidLoadResourceFromMemoryCache(const GURL& url,
                                         const std::string& security_info,
                                         const std::string& http_method,
                                         const std::string& mime_type,
                                         ResourceType::Type resource_type);
 
   // Force cancels any pending requests for the given process.
   void CancelRequestsForProcess(int child_id);
 
@@ skipping 75 matching lines @@
   // and places them in the given out params (both required). If there are no
   // such IDs associated with the request (such as non-page-related requests),
   // this function will return false and both out params will be -1.
   static bool RenderViewForRequest(const net::URLRequest* request,
                                    int* render_process_host_id,
                                    int* render_view_host_id);
 
   // A shutdown helper that runs on the IO thread.
   void OnShutdown();
 
+  // The real implementation of the OnSwapOutACK logic. Public methods call
+  // this method with the proper value for the timed_out parameter.
+  void HandleSwapOutACK(const ViewMsg_SwapOut_Params& params, bool timed_out);
+
   // Helper function for regular and download requests.
   void BeginRequestInternal(scoped_ptr<net::URLRequest> request,
                             scoped_ptr<ResourceHandler> handler);
 
   void StartLoading(ResourceRequestInfoImpl* info,
                     const linked_ptr<ResourceLoader>& loader);
 
   // Updates the "cost" of outstanding requests for |child_id|.
   // The "cost" approximates how many bytes are consumed by all the in-memory
   // data structures supporting this request (net::URLRequest object,
@@ skipping 146 matching lines @@
   // http://crbug.com/90971 - Assists in tracking down use-after-frees on
   // shutdown.
   std::set<const ResourceContext*> active_resource_contexts_;
 
   DISALLOW_COPY_AND_ASSIGN(ResourceDispatcherHostImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RESOURCE_DISPATCHER_HOST_IMPL_H_