Use a direct include of time headers in media/.

media/audio/audio_silence_detector.h

 // Copyright (c) 2013 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_AUDIO_AUDIO_SILENCE_DETECTOR_H_
 #define MEDIA_AUDIO_AUDIO_SILENCE_DETECTOR_H_
 
 #include "base/atomic_ref_count.h"
 #include "base/callback.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/threading/thread_checker.h"
-#include "base/timer.h"
+#include "base/timer/timer.h"
 #include "media/base/media_export.h"
 
 // An audio silence detector.  It is periodically provided an AudioBus by the
 // native audio thread, where simple logic determines whether the audio samples
 // in each channel in the buffer represent silence.  If a long-enough period of
 // contiguous silence is observed in all channels, a notification callback is
 // run on the thread that constructed AudioSilenceDetector.
 //
 // Note that extreme care has been taken to make the
 // AudioSilenceDetector::Scan() method safe to be called on the native audio
@@ skipping 80 matching lines @@
 
   // Constructor, destructor and most methods must be called on the same thread.
   base::ThreadChecker thread_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioSilenceDetector);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_AUDIO_SILENCE_DETECTOR_H_