Cancel the request when URLLoader is gone

content/browser/loader/mojo_async_resource_handler.cc

Index: content/browser/loader/mojo_async_resource_handler.cc
diff --git a/content/browser/loader/mojo_async_resource_handler.cc b/content/browser/loader/mojo_async_resource_handler.cc
index b66c389d3ff84b0a3af098cafe9dfbf060f2c835..4c2e97df66b6176a6fdfd97f467a31ca56b89beb 100644
--- a/content/browser/loader/mojo_async_resource_handler.cc
+++ b/content/browser/loader/mojo_async_resource_handler.cc
@@ -16,6 +16,7 @@
 #include "content/browser/loader/resource_dispatcher_host_impl.h"
 #include "content/browser/loader/resource_request_info_impl.h"
 #include "content/common/resource_request_completion_status.h"
+#include "content/public/browser/global_request_id.h"
 #include "content/public/browser/resource_dispatcher_host_delegate.h"
 #include "content/public/common/resource_response.h"
 #include "mojo/public/c/system/data_pipe.h"
@@ -111,6 +112,10 @@ MojoAsyncResourceHandler::MojoAsyncResourceHandler(
       url_loader_client_(std::move(url_loader_client)) {
   DCHECK(url_loader_client_);
   InitializeResourceBufferConstants();
+  // This unretained pointer is safe because the callback will never be called
+  // after |this| destruction.

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

nit:  "after |this| is destroyed."

Could optionally mention that this is because it owned binding_, but think we're
fine without it.

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

Done.

+  binding_.set_connection_error_handler(
+      base::Bind(&MojoAsyncResourceHandler::Cancel, base::Unretained(this)));
 }
 
 MojoAsyncResourceHandler::~MojoAsyncResourceHandler() {
@@ -237,10 +242,6 @@ void MojoAsyncResourceHandler::FollowRedirect() {
   NOTIMPLEMENTED();
 }
 
-void MojoAsyncResourceHandler::Cancel() {
-  NOTIMPLEMENTED();
-}
-
 void MojoAsyncResourceHandler::ResumeForTesting() {
   Resume();
 }
@@ -394,4 +395,10 @@ void MojoAsyncResourceHandler::OnWritable(MojoResult unused) {
   Resume();
 }
 
+void MojoAsyncResourceHandler::Cancel() {
+  const ResourceRequestInfoImpl* info = GetRequestInfo();
+  ResourceDispatcherHostImpl::Get()->CancelRequestFromRenderer(
+      GlobalRequestID(info->GetChildID(), info->GetRequestID()));
+}
+
 }  // namespace content