Cancel the request when URLLoader is gone

content/browser/loader/resource_dispatcher_host_impl.cc

 // 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.
 
 // See http://dev.chromium.org/developers/design-documents/multi-process-resource-loading
 
 #include "content/browser/loader/resource_dispatcher_host_impl.h"
 
 #include <stddef.h>
 
@@ skipping 1787 matching lines @@
 
   // Note that we don't remove the security bits here. This will be done
   // when all file refs are deleted (see RegisterDownloadedTempFile).
 }
 
 bool ResourceDispatcherHostImpl::Send(IPC::Message* message) {
   delete message;
   return false;
 }
 
-// Note that this cancel is subtly different from the other
-// CancelRequest methods in this file, which also tear down the loader.
 void ResourceDispatcherHostImpl::OnCancelRequest(int request_id) {
-  int child_id = filter_->child_id();
-
-  // When the old renderer dies, it sends a message to us to cancel its
-  // requests.
-  if (IsTransferredNavigation(GlobalRequestID(child_id, request_id)))
-    return;
-
-  ResourceLoader* loader = GetLoader(child_id, request_id);
-
-  // It is possible that the request has been completed and removed from the
-  // loader queue but the client has not processed the request completed message
-  // before issuing a cancel. This happens frequently for beacons which are
-  // canceled in the response received handler.
-  if (!loader)
-    return;
-
-  loader->CancelRequest(true);
+  CancelRequestFromRenderer(GlobalRequestID(filter_->child_id(), request_id));
 }
 
 ResourceRequestInfoImpl* ResourceDispatcherHostImpl::CreateRequestInfo(
     int child_id,
     int render_view_route_id,
     int render_frame_route_id,
     bool download,
     ResourceContext* context) {
   return new ResourceRequestInfoImpl(
       PROCESS_TYPE_RENDERER, child_id, render_view_route_id,
@@ skipping 608 matching lines @@
         true /* force_download */, true /* is_new_request */);
   }
   BeginRequestInternal(std::move(request), std::move(handler));
 }
 
 int ResourceDispatcherHostImpl::MakeRequestID() {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   return --request_id_;
 }
 
+void ResourceDispatcherHostImpl::CancelRequestFromRenderer(
+    GlobalRequestID request_id) {
+  // When the old renderer dies, it sends a message to us to cancel its
+  // requests.
+  if (IsTransferredNavigation(request_id))
+    return;
+
+  ResourceLoader* loader =
+      GetLoader(request_id.child_id, request_id.request_id);

[mmenke, 2016/11/03 18:17:41]

nit:  GetLoader(request_id) (There's an overload that takes the GlobalRequestID,
instead of the separate IDs)

[yhirano, 2016/11/08 11:52:23]

Done.

+
+  // It is possible that the request has been completed and removed from the
+  // loader queue but the client has not processed the request completed message
+  // before issuing a cancel. This happens frequently for beacons which are
+  // canceled in the response received handler.
+  if (!loader)
+    return;
+
+  loader->CancelRequest(true);
+}
+
 void ResourceDispatcherHostImpl::StartLoading(
     ResourceRequestInfoImpl* info,
     std::unique_ptr<ResourceLoader> loader) {
   // TODO(pkasting): Remove ScopedTracker below once crbug.com/456331 is fixed.
   tracked_objects::ScopedTracker tracking_profile(
       FROM_HERE_WITH_EXPLICIT_FUNCTION(
           "456331 ResourceDispatcherHostImpl::StartLoading"));
 
   ResourceLoader* loader_ptr = loader.get();
   DCHECK(pending_loaders_[info->GetGlobalRequestID()] == nullptr);
@@ skipping 324 matching lines @@
                                  &throttles);
     if (!throttles.empty()) {
       handler.reset(new ThrottlingResourceHandler(std::move(handler), request,
                                                   std::move(throttles)));
     }
   }
   return handler;
 }
 
 }  // namespace content