ResourceScheduler should use renderer notifications instead of MRUCache to track renderers.

content/browser/loader/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
 
 #ifndef CONTENT_BROWSER_LOADER_RESOURCE_DISPATCHER_HOST_IMPL_H_
 #define CONTENT_BROWSER_LOADER_RESOURCE_DISPATCHER_HOST_IMPL_H_
 
 #include <map>
 #include <set>
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/linked_ptr.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/observer_list.h"
 #include "base/time.h"
 #include "base/timer.h"
 #include "content/browser/download/download_resource_handler.h"
+#include "content/browser/loader/render_view_host_tracker.h"
 #include "content/browser/loader/resource_loader.h"
 #include "content/browser/loader/resource_loader_delegate.h"
 #include "content/browser/loader/resource_scheduler.h"
 #include "content/common/content_export.h"
 #include "content/public/browser/child_process_data.h"
 #include "content/public/browser/download_id.h"
 #include "content/public/browser/notification_types.h"
 #include "content/public/browser/resource_dispatcher_host.h"
 #include "ipc/ipc_message.h"
 #include "net/cookies/canonical_cookie.h"
@@ skipping 122 matching lines @@
   // 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);
 
+  // Called when a RenderViewHost is created.
+  void OnRenderViewHostCreated(int child_id, int route_id);
+
+  // Called when a RenderViewHost is deleted.
+  void OnRenderViewHostDeleted(int child_id, int route_id);
+
   // Force cancels any pending requests for the given process.
   void CancelRequestsForProcess(int child_id);
 
-  // Force cancels any pending requests for the given route id.  This method
-  // acts like CancelRequestsForProcess when route_id is -1.
-  void CancelRequestsForRoute(int child_id, int route_id);
-
   void OnUserGesture(WebContentsImpl* contents);
 
   // Retrieves a net::URLRequest.  Must be called from the IO thread.
   net::URLRequest* GetURLRequest(const GlobalRequestID& request_id);
 
   void RemovePendingRequest(int child_id, int request_id);
 
   // Cancels any blocked request for the specified route id.
   void CancelBlockedRequestsForRoute(int child_id, int route_id);
 
@@ skipping 96 matching lines @@
   // data structures supporting this request (net::URLRequest object,
   // HttpNetworkTransaction, etc...).
   // The value of |cost| is added to the running total, and the resulting
   // sum is returned.
   int IncrementOutstandingRequestsMemoryCost(int cost,
                                              int child_id);
 
   // Estimate how much heap space |request| will consume to run.
   static int CalculateApproximateMemoryCost(net::URLRequest* request);
 
+  // Force cancels any pending requests for the given route id.  This method
+  // acts like CancelRequestsForProcess when route_id is -1.
+  void CancelRequestsForRoute(int child_id, int route_id);
+
   // The list of all requests that we have pending. This list is not really
   // optimized, and assumes that we have relatively few requests pending at once
   // since some operations require brute-force searching of the list.
   //
   // It may be enhanced in the future to provide some kind of prioritization
   // mechanism. We should also consider a hashtable or binary tree if it turns
   // out we have a lot of things here.
   typedef std::map<GlobalRequestID, linked_ptr<ResourceLoader> > LoaderMap;
 
   // Deletes the pending request identified by the iterator passed in.
@@ skipping 127 matching lines @@
   // http://crbug.com/90971 - Assists in tracking down use-after-frees on
   // shutdown.
   std::set<const ResourceContext*> active_resource_contexts_;
 
   typedef std::map<GlobalRequestID,
                    ObserverList<ResourceMessageDelegate>*> DelegateMap;
   DelegateMap delegate_map_;
 
   scoped_ptr<ResourceScheduler> scheduler_;
 
+  RenderViewHostTracker tracker_;  // Lives on UI thread.
+
   DISALLOW_COPY_AND_ASSIGN(ResourceDispatcherHostImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_LOADER_RESOURCE_DISPATCHER_HOST_IMPL_H_