Change media MessageLoopProxy usage to SingleThreadTaskRunners.

content/renderer/render_thread_impl.h

Index: content/renderer/render_thread_impl.h
diff --git a/content/renderer/render_thread_impl.h b/content/renderer/render_thread_impl.h
index 68828f67cb87210463264b595da4765f758ac17b..ea65fd28a7230b852ea4de4881f2b02b6cfcf401 100644
--- a/content/renderer/render_thread_impl.h
+++ b/content/renderer/render_thread_impl.h
@@ -297,10 +297,10 @@ class CONTENT_EXPORT RenderThreadImpl : public RenderThread,
   // on the renderer's main thread.
   scoped_refptr<base::MessageLoopProxy> GetFileThreadMessageLoopProxy();
 
-  // Returns a MessageLoopProxy instance corresponding to the message loop
+  // Returns a SingleThreadTaskRunner instance corresponding to the message loop
   // of the thread on which media operations should be run. Must be called
   // on the renderer's main thread.
-  scoped_refptr<base::MessageLoopProxy> GetMediaThreadMessageLoopProxy();
+  scoped_refptr<base::SingleThreadTaskRunner> GetMediaThreadTaskRunner();
 
   // Causes the idle handler to skip sending idle notifications
   // on the two next scheduled calls, so idle notifications are