Part 1: Plumb render view ID to render host

content/common/media/audio_messages.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.
 
 // IPC messages for the audio.
 // Multiply-included message file, hence no include guard.
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 72 matching lines @@
                      int /* stream id */,
                      double /* volume */)
 
 IPC_MESSAGE_CONTROL2(AudioInputMsg_NotifyDeviceStarted,
                      int /* stream id */,
                      std::string /* device_id */)
 
 // Messages sent from the renderer to the browser.
 
 // Request that got sent to browser for creating an audio output stream
-IPC_MESSAGE_CONTROL2(AudioHostMsg_CreateStream,
+IPC_MESSAGE_CONTROL3(AudioHostMsg_CreateStream,
+                     int /* render view id */,
                      int /* stream_id */,
                      media::AudioParameters /* params */)
 
 // Request that got sent to browser for creating an audio input stream
 IPC_MESSAGE_CONTROL4(AudioInputHostMsg_CreateStream,
                      int /* stream_id */,
                      media::AudioParameters /* params */,
                      std::string /* device_id */,
                      bool /* automatic_gain_control */)
 
@@ skipping 30 matching lines @@
 // Set audio volume of the input stream specified by stream_id.
 IPC_MESSAGE_CONTROL2(AudioInputHostMsg_SetVolume,
                      int /* stream_id */,
                      double /* volume */)
 
 // Start the device referenced by the session_id for the input stream specified
 // by stream_id.
 IPC_MESSAGE_CONTROL2(AudioInputHostMsg_StartDevice,
                      int /* stream_id */,
                      int /* session_id */)