Do not pass the string device_id via IPC message to create an audio input stream

media/audio/audio_input_ipc.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_AUDIO_INPUT_IPC_H_
 #define MEDIA_AUDIO_AUDIO_INPUT_IPC_H_
 
 #include "base/shared_memory.h"
 #include "base/sync_socket.h"
 #include "media/audio/audio_parameters.h"
@@ skipping 24 matching lines @@
   virtual void OnStreamCreated(base::SharedMemoryHandle handle,
                                base::SyncSocket::Handle socket_handle,
                                int length) = 0;
 
   // Called when state of an audio stream has changed.
   virtual void OnStateChanged(State state) = 0;
 
   // Called when the input stream volume has changed.
   virtual void OnVolume(double volume) = 0;
 
-  // Called when a device has been started on the server side.
-  // If the device could not be started, |device_id| will be empty.
-  virtual void OnDeviceReady(const std::string& device_id) = 0;
-
   // Called when the AudioInputIPC object is going away and/or when the
   // IPC channel has been closed and no more IPC requests can be made.
   // Implementations must clear any references to the AudioInputIPC object
   // at this point.
   virtual void OnIPCClosed() = 0;
 
  protected:
   virtual ~AudioInputIPCDelegate();
 };
 
@@ skipping 10 matching lines @@
   // Unregisters a delegate that was previously registered via a call to
   // AddDelegate().  The audio stream should be in a closed state prior to
   // calling this function.
   virtual void RemoveDelegate(int stream_id) = 0;
 
   // Sends a request to create an AudioInputController object in the peer
   // process, identify it by |stream_id| and configure it to use the specified
   // audio |params|.  Once the stream has been created, the implementation must
   // generate a notification to the AudioInputIPCDelegate and call
   // OnStreamCreated().
-  virtual void CreateStream(int stream_id, const AudioParameters& params,
-      const std::string& device_id, bool automatic_gain_control) = 0;
-
-  // Starts the device on the server side.  Once the device has started,
-  // or failed to start, a callback to
-  // AudioInputIPCDelegate::OnDeviceReady() must be made.
-  virtual void StartDevice(int stream_id, int session_id) = 0;
+  virtual void CreateStream(int stream_id, int session_id,
+                            const AudioParameters& params,
+                            bool automatic_gain_control) = 0;
 
   // Corresponds to a call to AudioInputController::Record() on the server side.
   virtual void RecordStream(int stream_id) = 0;
 
   // Sets the volume of the audio stream.
   virtual void SetVolume(int stream_id, double volume) = 0;
 
   // Closes the audio stream and deletes the matching AudioInputController
   // instance.  Prior to deleting the AudioInputController object, a call to
   // AudioInputController::Close must be made.
   virtual void CloseStream(int stream_id) = 0;
 
  protected:
   virtual ~AudioInputIPC();
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_AUDIO_INPUT_IPC_H_