Replace MessageLoopProxy with SingleThreadTaskRunner for media/filters/ + associated code.

media/base/bind_to_loop.h.pump

 $$ This is a pump file for generating file templates.  Pump is a python
 $$ script that is part of the Google Test suite of utilities.  Description
 $$ can be found here:
 $$
 $$ http://code.google.com/p/googletest/wiki/PumpManual
 $$
 
 $$ See comment for MAX_ARITY in base/bind.h.pump.
 $var MAX_ARITY = 7
 
 // Copyright (c) 2012 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.
 
 #ifndef MEDIA_BASE_BIND_TO_LOOP_H_
 #define MEDIA_BASE_BIND_TO_LOOP_H_
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/message_loop/message_loop_proxy.h"
+#include "base/single_thread_task_runner.h"
 
 // This is a helper utility for base::Bind()ing callbacks on to particular
 // MessageLoops.  A typical use is when |a| (of class |A|) wants to hand a
 // callback such as base::Bind(&A::AMethod, a) to |b|, but needs to ensure that
 // when |b| executes the callback, it does so on a particular MessageLoop.
 //
 // Typical usage: request to be called back on the current thread:
 // other->StartAsyncProcessAndCallMeBack(
 //    media::BindToLoop(MessageLoopProxy::current(),
 //                      base::Bind(&MyClass::MyMethod, this)));
@@ skipping 24 matching lines @@
 
 template <typename T> struct TrampolineHelper;
 
 $range ARITY 0..MAX_ARITY
 $for ARITY [[
 $range ARG 1..ARITY
 
 template <$for ARG , [[typename A$(ARG)]]>
 struct TrampolineHelper<void($for ARG , [[A$(ARG)]])> {
   static void Run(
-      const scoped_refptr<base::MessageLoopProxy>& loop,
+      const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
       const base::Callback<void($for ARG , [[A$(ARG)]])>& cb
 $if ARITY != 0 [[, ]]
 $for ARG , [[A$(ARG) a$(ARG)]]
 ) {
-    loop->PostTask(FROM_HERE, base::Bind(cb
+    task_runner->PostTask(FROM_HERE, base::Bind(cb
 $if ARITY != 0 [[, ]]
 $for ARG , [[internal::TrampolineForward(a$(ARG))]]));
   }
 };
 
 
 ]]  $$ for ARITY
 
 }  // namespace internal
 
 template<typename T>
 static base::Callback<T> BindToLoop(
-    const scoped_refptr<base::MessageLoopProxy>& loop,
+    const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
     const base::Callback<T>& cb) {
-  return base::Bind(&internal::TrampolineHelper<T>::Run, loop, cb);
+  return base::Bind(&internal::TrampolineHelper<T>::Run, task_runner, cb);
 }
 
 template<typename T>
 static base::Callback<T> BindToCurrentLoop(
     const base::Callback<T>& cb) {
   return BindToLoop(base::MessageLoopProxy::current(), cb);
 }
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_BIND_TO_LOOP_H_