handle the case when device is closed before media pipeline is fully initialized.

content/browser/renderer_host/media/video_capture_host.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.
 //
 // VideoCaptureHost serves video capture related messages from
 // VideCaptureMessageFilter which lives inside the render process.
 //
 // This class is owned by BrowserRenderProcessHost, and instantiated on UI
 // thread, but all other operations and method calls happen on IO thread.
 //
@@ skipping 60 matching lines @@
   virtual void OnBufferCreated(const VideoCaptureControllerID& id,
                                base::SharedMemoryHandle handle,
                                int length, int buffer_id) OVERRIDE;
   virtual void OnBufferReady(const VideoCaptureControllerID& id,
                              int buffer_id,
                              base::Time timestamp) OVERRIDE;
   virtual void OnFrameInfo(const VideoCaptureControllerID& id,
                            int width,
                            int height,
                            int frame_per_second) OVERRIDE;
+  virtual void OnPaused(const VideoCaptureControllerID& id) OVERRIDE;
   virtual void OnReadyToDelete(const VideoCaptureControllerID& id) OVERRIDE;
 
  private:
   friend class content::BrowserThread;
   friend class base::DeleteHelper<VideoCaptureHost>;
   friend class MockVideoCaptureHost;
   friend class VideoCaptureHostTest;
 
   virtual ~VideoCaptureHost();
 
@@ skipping 16 matching lines @@
   // IPC message: Pause capture on device referenced by |device_id|.
   void OnPauseCapture(int device_id);
 
   // IPC message: Receive an empty buffer from renderer. Send it to device
   // referenced by |device_id|.
   void OnReceiveEmptyBuffer(int device_id, int buffer_id);
 
 
   // Called on the IO thread when VideoCaptureController have
   // reported that all DIBs have been returned.
-  void DoDeleteVideoCaptureController(const VideoCaptureControllerID& id);
+  void DoDeleteVideoCaptureControllerOnIOThread(
+      const VideoCaptureControllerID& id);
 
   // Send a newly created buffer to the VideoCaptureMessageFilter.
-  void DoSendNewBuffer(int device_id,
-                       base::SharedMemoryHandle handle,
-                       int length,
-                       int buffer_id);
+  void DoSendNewBufferOnIOThread(int device_id,
+                                 base::SharedMemoryHandle handle,
+                                 int length,
+                                 int buffer_id);
 
   // Send a filled buffer to the VideoCaptureMessageFilter.
-  void DoSendFilledBuffer(int device_id,
-                          int buffer_id,
-                          base::Time timestamp);
+  void DoSendFilledBufferOnIOThread(int device_id,
+                                    int buffer_id,
+                                    base::Time timestamp);
 
   // Send a information about frame resolution and frame rate
   // to the VideoCaptureMessageFilter.
-  void DoSendFrameInfo(int device_id,
-                       int width,
-                       int height,
-                       int frame_per_second);
+  void DoSendFrameInfoOnIOThread(int device_id,
+                                 int width,
+                                 int height,
+                                 int frame_per_second);
 
   // Handle error coming from VideoCaptureDevice.
-  void DoHandleError(int device_id);
+  void DoHandleErrorOnIOThread(int device_id);
+
+  void DoPausedOnIOThread(int device_id);
 
   // Helpers.
   media_stream::VideoCaptureManager* GetVideoCaptureManager();
 
   struct Entry;
   typedef std::map<VideoCaptureControllerID, Entry*> EntryMap;
   // A map of VideoCaptureControllerID to its state and VideoCaptureController.
   EntryMap entries_;
 
   // Used to get a pointer to VideoCaptureManager to start/stop capture devices.
   content::ResourceContext* resource_context_;
   media::AudioManager* audio_manager_;
 
   DISALLOW_COPY_AND_ASSIGN(VideoCaptureHost);
 };
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_VIDEO_CAPTURE_HOST_H_