base::Bind: Remove callback_old.h.

chrome/browser/chromeos/audio_mixer.h

Index: chrome/browser/chromeos/audio_mixer.h
diff --git a/chrome/browser/chromeos/audio_mixer.h b/chrome/browser/chromeos/audio_mixer.h
index 3187ed5a88e772cd8809a2bed1a018e4a73059d1..ba88736f92d11f7fbccdbb581914ce178d5bbf27 100644
--- a/chrome/browser/chromeos/audio_mixer.h
+++ b/chrome/browser/chromeos/audio_mixer.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -7,7 +7,6 @@
 #pragma once
 
 #include "base/basictypes.h"
-#include "base/callback_old.h"
 
 namespace chromeos {