Move passing of WebRTC rendering frames to IO thread

content/renderer/render_frame_impl.cc

 // Copyright 2013 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.
 
 #include "content/renderer/render_frame_impl.h"
 
 #include <map>
 #include <string>
 #include <utility>
 #include <vector>
@@ skipping 6010 matching lines @@
   RenderThreadImpl* const render_thread = RenderThreadImpl::current();
 
   scoped_refptr<base::SingleThreadTaskRunner> compositor_task_runner =
       render_thread->compositor_task_runner();
   if (!compositor_task_runner.get())
     compositor_task_runner = base::ThreadTaskRunnerHandle::Get();
 
   return new WebMediaPlayerMS(
       frame_, client, GetWebMediaPlayerDelegate()->AsWeakPtr(),
       new RenderMediaLog(url::Origin(security_origin).GetURL()),
-      CreateRendererFactory(), compositor_task_runner,
-      render_thread->GetMediaThreadTaskRunner(),
+      CreateRendererFactory(), render_thread->GetIOTaskRunner(),
+      compositor_task_runner, render_thread->GetMediaThreadTaskRunner(),
       render_thread->GetWorkerTaskRunner(), render_thread->GetGpuFactories(),
       sink_id, security_origin);
 #else
   return NULL;
 #endif  // BUILDFLAG(ENABLE_WEBRTC)
 }
 
 std::unique_ptr<MediaStreamRendererFactory>
 RenderFrameImpl::CreateRendererFactory() {
   std::unique_ptr<MediaStreamRendererFactory> factory =
@@ skipping 628 matching lines @@
   // event target. Potentially a Pepper plugin will receive the event.
   // In order to tell whether a plugin gets the last mouse event and which it
   // is, we set |pepper_last_mouse_event_target_| to null here. If a plugin gets
   // the event, it will notify us via DidReceiveMouseEvent() and set itself as
   // |pepper_last_mouse_event_target_|.
   pepper_last_mouse_event_target_ = nullptr;
 #endif
 }
 
 }  // namespace content