Forward the number of skipped frames by the OS in audio playout.

media/audio/mac/audio_auhal_mac.h

 // Copyright 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.
 //
 // Implementation notes:
 //
 // - It is recommended to first acquire the native sample rate of the default
 //   output device and then use the same rate when creating this object.
 //   Use AudioManagerMac::HardwareSampleRate() to retrieve the sample rate.
 // - Calling Close() also leads to self destruction.
@@ skipping 108 matching lines @@
   // Creates the input and output busses.
   void CreateIOBusses();
 
   // Gets the fixed playout device hardware latency and stores it. Returns 0
   // if not available.
   double GetHardwareLatency();
 
   // Gets the current playout latency value.
   double GetPlayoutLatency(const AudioTimeStamp* output_time_stamp);
 
-  void UpdatePlayoutTimestamp(const AudioTimeStamp* timestamp);
+  // Updates playout timestamp and total lost frames and glitches stats. Returns
+  // the number of lost frames (this render data request).
+  UInt32 UpdatePlayoutTimestampAndStats(const AudioTimeStamp* timestamp);
 
   // Called from the dtor and when the stream is reset.
   void ReportAndResetStats();
 
   // Our creator, the audio manager needs to be notified when we close.
   AudioManagerMac* const manager_;
 
   const AudioParameters params_;
   // For convenience - same as in params_.
   const int output_channels_;
@@ skipping 62 matching lines @@
   // Used to make sure control functions (Start(), Stop() etc) are called on the
   // right thread.
   base::ThreadChecker thread_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(AUHALStream);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_MAC_AUDIO_AUHAL_MAC_H_