Move the device enumerate/open/close work to device thread from IO thread

media/video/capture/win/video_capture_device_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.
 
 // Windows specific implementation of VideoCaptureDevice.
 // DirectShow is used for capturing. DirectShow provide its own threads
 // for capturing.
 
 #ifndef MEDIA_VIDEO_CAPTURE_WIN_VIDEO_CAPTURE_DEVICE_WIN_H_
 #define MEDIA_VIDEO_CAPTURE_WIN_VIDEO_CAPTURE_DEVICE_WIN_H_
 #pragma once
 
 // Avoid including strsafe.h via dshow as it will cause build warnings.
 #define NO_DSHOW_STRSAFE
 #include <dshow.h>
 
 #include <map>
 #include <string>
 
+#include "base/threading/non_thread_safe.h"
 #include "base/threading/thread.h"
-#include "base/win/scoped_com_initializer.h"
 #include "base/win/scoped_comptr.h"
 #include "media/video/capture/video_capture_device.h"
 #include "media/video/capture/video_capture_types.h"
 #include "media/video/capture/win/sink_filter_win.h"
 #include "media/video/capture/win/sink_input_pin_win.h"
 
 namespace media {
 
+// All the methods in the class can only be run on a COM initialized thread.
 class VideoCaptureDeviceWin
-    : public VideoCaptureDevice,
+    : public base::NonThreadSafe,
+      public VideoCaptureDevice,
       public SinkFilterObserver {
  public:
   explicit VideoCaptureDeviceWin(const Name& device_name);
   virtual ~VideoCaptureDeviceWin();
   // Opens the device driver for this device.
   // This function is used by the static VideoCaptureDevice::Create function.
   bool Init();
 
   // VideoCaptureDevice implementation.
   virtual void Allocate(int width,
@@ skipping 15 matching lines @@
   };
   typedef std::map<int, VideoCaptureCapability> CapabilityMap;
 
   // Implements SinkFilterObserver.
   virtual void FrameReceived(const uint8* buffer, int length);
 
   bool CreateCapabilityMap();
   int GetBestMatchedCapability(int width, int height, int frame_rate);
   void SetErrorState(const char* reason);
 
-  base::win::ScopedCOMInitializer initialize_com_;
-
   Name device_name_;
   InternalState state_;
   VideoCaptureDevice::EventHandler* observer_;
 
   base::win::ScopedComPtr<IBaseFilter> capture_filter_;
   base::win::ScopedComPtr<IGraphBuilder> graph_builder_;
   base::win::ScopedComPtr<IMediaControl> media_control_;
   base::win::ScopedComPtr<IPin> input_sink_pin_;
   base::win::ScopedComPtr<IPin> output_capture_pin_;
   // Used when using a MJPEG decoder.
   base::win::ScopedComPtr<IBaseFilter> mjpg_filter_;
   base::win::ScopedComPtr<IPin> input_mjpg_pin_;
   base::win::ScopedComPtr<IPin> output_mjpg_pin_;
 
   scoped_refptr<SinkFilter> sink_filter_;
 
   // Map of all capabilities this device support.
   CapabilityMap capabilities_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(VideoCaptureDeviceWin);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_VIDEO_CAPTURE_WIN_VIDEO_CAPTURE_DEVICE_WIN_H_