Fix outstanding request stats for multiple transfer navigations.

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
@@ skipping 231 matching lines @@
       net::URLRequest* request,
       ResourceResponse* response,
       std::string* payload);
 
   ResourceScheduler* scheduler() { return scheduler_.get(); }
 
   // Called by a ResourceHandler when it's ready to start reading data and
   // sending it to the renderer. Returns true if there are enough file
   // descriptors available for the shared memory buffer. If false is returned,
   // the request should cancel.
-  bool HasSufficientResourcesForRequest(const net::URLRequest* request_);

[Charlie Reis, 2014/10/14 23:54:12]

No idea how |request_| slipped in as a parameter name.

+  bool HasSufficientResourcesForRequest(net::URLRequest* request);
 
   // Called by a ResourceHandler after it has finished its request and is done
   // using its shared memory buffer. Frees up that file descriptor to be used
   // elsewhere.
-  void FinishedWithResourcesForRequest(const net::URLRequest* request_);
+  void FinishedWithResourcesForRequest(net::URLRequest* request);
 
   // PlzNavigate
   // Called by NavigationRequest to start a navigation request in the node
   // identified by |frame_node_id|.
   void StartNavigationRequest(const CommonNavigationParams& common_params,
                               const NavigationRequestInfo& info,
                               scoped_refptr<ResourceRequestBody> request_body,
                               int64 navigation_request_id,
                               int64 frame_node_id);
 
@@ skipping 68 matching lines @@
   // the renderer that made the request in |info|.
   void UpdateOutstandingRequestsStats(const ResourceRequestInfoImpl& info,
                                       const OustandingRequestsStats& stats);
 
   // Called every time an outstanding request is created or deleted. |count|
   // indicates whether the request is new or deleted. |count| must be 1 or -1.
   OustandingRequestsStats IncrementOutstandingRequestsMemory(
       int count,
       const ResourceRequestInfoImpl& info);
 
-  // Called every time an in flight request is issued or finished. |count|
-  // indicates whether the request is issuing or finishing. |count| must be 1
-  // or -1.
+  // Called when in flight requests that require file descriptors for their
+  // shared memory buffers are issued or finished. |count| indicates whether the

[davidben, 2014/10/15 19:15:12]

First sentence should probably say:

  Called when an flight request allocates or releases a shared memory buffer.

It's not allocated when the request is issued. Just when we first need the
buffer in ARH::OnWillRead. (I guess another option would be to count it ahead of
time because the RDH knows which requests end at ARHs and which end at different
leaf handlers. The current logic delays until we start reading the response
body.)

[Charlie Reis, 2014/10/15 19:48:00]

Done.

+  // request is issuing or finishing. |count| must be 1 or -1.
   OustandingRequestsStats IncrementOutstandingRequestsCount(
       int count,
-      const ResourceRequestInfoImpl& info);
+      ResourceRequestInfoImpl& info);
 
   // 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
@@ skipping 182 matching lines @@
   DelegateMap delegate_map_;
 
   scoped_ptr<ResourceScheduler> scheduler_;
 
   DISALLOW_COPY_AND_ASSIGN(ResourceDispatcherHostImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_LOADER_RESOURCE_DISPATCHER_HOST_IMPL_H_