Fix errors in comments. Make comments match code.

media/base/channel_mixer.h

 // 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_CHANNEL_MIXER_H_
 #define MEDIA_BASE_CHANNEL_MIXER_H_
 
 #include <vector>
 
-#include "base/basictypes.h"
+#include "base/macros.h"
 #include "media/base/channel_layout.h"
 #include "media/base/media_export.h"
 
 namespace media {
 
 class AudioBus;
 class AudioParameters;
 
 // ChannelMixer is for converting audio between channel layouts.  The conversion
 // matrix is built upon construction and used during each Transform() call.  The
@@ skipping 20 matching lines @@
   // Optimization case for when we can simply remap the input channels to output
   // channels and don't need to do a multiply-accumulate loop over |matrix_|.
   bool remapping_;
 
   DISALLOW_COPY_AND_ASSIGN(ChannelMixer);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_CHANNEL_MIXER_H_