Adds COM init to AudioManager thread for Windows

media/audio/win/audio_low_latency_input_win.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.
 //
 // Implementation of AudioInputStream for Windows using Windows Core Audio
 // WASAPI for low latency capturing.
 //
 // Overview of operation:
 //
 // - An object of WASAPIAudioInputStream is created by the AudioManager
@@ skipping 17 matching lines @@
 // - This implementation is single-threaded, hence:
 //    o Construction and destruction must take place from the same thread.
 //    o It is recommended to call all APIs from the same thread as well.
 // - It is recommended to first acquire the native sample rate of the default
 //   input device and then use the same rate when creating this object. Use
 //   WASAPIAudioInputStream::HardwareSampleRate() to retrieve the sample rate.
 // - Calling Close() also leads to self destruction.
 //
 // Core Audio API details:
 //
-// - CoInitializeEx() is called on the creating thread and on the internal
-//   capture thread. Each thread's concurrency model and apartment is set
-//   to multi-threaded (MTA). CHECK() is called to ensure that we crash if
-//   CoInitializeEx(MTA) fails.
 // - Utilized MMDevice interfaces:
 //     o IMMDeviceEnumerator
 //     o IMMDevice
 // - Utilized WASAPI interfaces:
 //     o IAudioClient
 //     o IAudioCaptureClient
 // - The stream is initialized in shared mode and the processing of the
 //   audio buffer is event driven.
 // - The Multimedia Class Scheduler service (MMCSS) is utilized to boost
 //   the priority of the capture thread.
@@ skipping 75 matching lines @@
   HRESULT ActivateCaptureDevice();
   HRESULT GetAudioEngineStreamFormat();
   bool DesiredFormatIsSupported();
   HRESULT InitializeAudioEngine();
 
   // Retrieves the stream format that the audio engine uses for its internal
   // processing/mixing of shared-mode streams.
   static HRESULT GetMixFormat(const std::string& device_id,
                               WAVEFORMATEX** device_format);
 
-  // Initializes the COM library for use by the calling thread and set the
-  // thread's concurrency model to multi-threaded.
-  base::win::ScopedCOMInitializer com_init_;
-
   // Our creator, the audio manager needs to be notified when we close.
   AudioManagerWin* manager_;
 
   // Capturing is driven by this thread (which has no message loop).
   // All OnData() callbacks will be called from this thread.
   base::DelegateSimpleThread* capture_thread_;
 
   // Contains the desired audio format which is set up at construction.
   WAVEFORMATEX format_;
 
@@ skipping 57 matching lines @@
 
   // This event will be signaled when capturing shall stop.
   base::win::ScopedHandle stop_capture_event_;
 
   DISALLOW_COPY_AND_ASSIGN(WASAPIAudioInputStream);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_WIN_AUDIO_LOW_LATENCY_INPUT_WIN_H_