Replace MessageLoopProxy with SingleThreadTaskRunner for the rest of media/.

media/midi/midi_manager.h

Index: media/midi/midi_manager.h
diff --git a/media/midi/midi_manager.h b/media/midi/midi_manager.h
index 6a301a942d9d1d6222c0e49587ef234951f8bba3..19ed53a03dd3baf87428b6c4dd36f7f1d239da13 100644
--- a/media/midi/midi_manager.h
+++ b/media/midi/midi_manager.h
@@ -9,13 +9,14 @@
 #include <vector>
 
 #include "base/basictypes.h"
+#include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
-#include "base/message_loop/message_loop_proxy.h"
 #include "base/synchronization/lock.h"
 #include "media/base/media_export.h"
 #include "media/midi/midi_port_info.h"
 
 namespace base {
+class SingleThreadTaskRunner;
 class Thread;
 }
 
@@ -123,7 +124,7 @@ class MEDIA_EXPORT MIDIManager {
   // |send_thread_| is used to send MIDI data by calling the platform-specific
   // API.
   scoped_ptr<base::Thread> send_thread_;
-  scoped_refptr<base::MessageLoopProxy> send_message_loop_;
+  scoped_refptr<base::SingleThreadTaskRunner> send_message_loop_;
 
   DISALLOW_COPY_AND_ASSIGN(MIDIManager);
 };