Revert of Revert of Remove the last piece of deprecated synchronous IO code.

media/audio/cras/cras_unified.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.
 //
 // Creates a unified stream based on the cras (ChromeOS audio server) interface.
 //
 // CrasUnifiedStream object is *not* thread-safe and should only be used
 // from the audio thread.
 
 #ifndef MEDIA_AUDIO_LINUX_CRAS_UNIFIED_H_
@@ skipping 52 matching lines @@
                          int err,
                          void* arg);
 
   // Chooses the correct audio callback based on stream direction.
   uint32 DispatchCallback(size_t frames,
                           uint8* input_samples,
                           uint8* output_samples,
                           const timespec* input_ts,
                           const timespec* output_ts);
 
-  // Receives input samples and write output samples for a unified I/O stream.
-  uint32 ReadWriteAudio(size_t frames,
-                        uint8* input_samples,
-                        uint8* output_samples,
-                        const timespec* input_ts,
-                        const timespec* output_ts);
-
   // Writes audio for a playback stream.
   uint32 WriteAudio(size_t frames, uint8* buffer, const timespec* sample_ts);
 
   // Deals with an error that occured in the stream.  Called from StreamError().
   void NotifyStreamError(int err);
 
   // The client used to communicate with the audio server.
   cras_client* client_;
 
   // ID of the playing stream.
@@ skipping 11 matching lines @@
   // Volume level from 0.0 to 1.0.
   float volume_;
 
   // Audio manager that created us.  Used to report that we've been closed.
   AudioManagerCras* manager_;
 
   // Callback to get audio samples.
   AudioSourceCallback* source_callback_;
 
   // Container for exchanging data with AudioSourceCallback::OnMoreData().
-  scoped_ptr<AudioBus> input_bus_;
   scoped_ptr<AudioBus> output_bus_;
 
   // Direciton of the stream.
   CRAS_STREAM_DIRECTION stream_direction_;
 
   DISALLOW_COPY_AND_ASSIGN(CrasUnifiedStream);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_LINUX_CRAS_UNIFIED_H_