Cancel the request when URLLoader is gone

content/browser/loader/resource_dispatcher_host_impl.cc

Index: content/browser/loader/resource_dispatcher_host_impl.cc
diff --git a/content/browser/loader/resource_dispatcher_host_impl.cc b/content/browser/loader/resource_dispatcher_host_impl.cc
index 16be639f7207a921d5403da720bf1ea16cb5d07e..1343bc9a1381e63410f791d4a5be326569cbc222 100644
--- a/content/browser/loader/resource_dispatcher_host_impl.cc
+++ b/content/browser/loader/resource_dispatcher_host_impl.cc
@@ -1805,26 +1805,8 @@ bool ResourceDispatcherHostImpl::Send(IPC::Message* 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(
@@ -2453,6 +2435,28 @@ int ResourceDispatcherHostImpl::MakeRequestID() {
   return --request_id_;
 }
 
+// Note that this cancel is subtly different from the other
+// CancelRequest methods in this file, which also tear down the loader.

[mmenke, 2016/11/01 13:52:32]

Existing bug, but class-level comments should go with method declaration, not
the definition.

[yhirano, 2016/11/02 06:02:56]

Done.

+void ResourceDispatcherHostImpl::CancelRequestFromRenderer(

[mmenke, 2016/11/01 13:52:32]

Why the new method?

[yhirano, 2016/11/01 14:24:25]

OnCancelRequest expects that |filter_| is set, but we can't do that from outside
of this class.

+    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);
+
+  // 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) {