Reduce high latency input buffers to 1.

media/audio/mac/audio_input_mac.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_AUDIO_MAC_AUDIO_INPUT_MAC_H_
 #define MEDIA_AUDIO_MAC_AUDIO_INPUT_MAC_H_
 
 #include <AudioToolbox/AudioQueue.h>
 #include <AudioToolbox/AudioFormat.h>
 
@@ skipping 44 matching lines @@
       UInt32 num_packets,
       const AudioStreamPacketDescription* desc);
 
   // Handles callback from OS. Will be called on OS internal thread.
   void HandleInputBuffer(AudioQueueRef audio_queue,
                          AudioQueueBufferRef audio_buffer,
                          const AudioTimeStamp* start_time,
                          UInt32 num_packets,
                          const AudioStreamPacketDescription* packet_desc);
 
-  static const int kNumberBuffers = 3;
+  static const int kNumberBuffers = 1;
 
   // Manager that owns this stream, used for closing down.
   AudioManagerBase* manager_;
   // We use the callback mostly to periodically supply the recorded audio data.
   AudioInputCallback* callback_;
   // Structure that holds the stream format details such as bitrate.
   AudioStreamBasicDescription format_;
   // Handle to the OS audio queue object.
   AudioQueueRef audio_queue_;
   // Size of each of the buffers in |audio_buffers_|
   uint32 buffer_size_bytes_;
   // True iff Start() has been called successfully.
   bool started_;
 
   DISALLOW_COPY_AND_ASSIGN(PCMQueueInAudioInputStream);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_MAC_AUDIO_INPUT_MAC_H_