[Reland] Post loading tasks on the appropriate WebFrameScheduler's queue

content/child/request_info.h

Index: content/child/request_info.h
diff --git a/content/child/request_info.h b/content/child/request_info.h
index e610ac8917554029957dc123b36c938033908f7b..fdf5de6ce3210e9fbf9652222196607959a2972a 100644
--- a/content/child/request_info.h
+++ b/content/child/request_info.h
@@ -9,6 +9,7 @@
 
 #include <string>
 
+#include "base/single_thread_task_runner.h"
 #include "content/common/content_export.h"
 #include "content/common/service_worker/service_worker_types.h"
 #include "content/public/common/referrer.h"
@@ -110,6 +111,9 @@ struct CONTENT_EXPORT RequestInfo {
   // Extra data associated with this request.  We do not own this pointer.
   blink::WebURLRequest::ExtraData* extra_data;
 
+  // Optional, the specific task queue to execute loading tasks on.
+  scoped_refptr<base::SingleThreadTaskRunner> loading_task_queue;
+
  private:
   DISALLOW_COPY_AND_ASSIGN(RequestInfo);
 };