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

content/browser/renderer_host/media/video_capture_manager.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.
 
 // VideoCaptureManager is used to open/close, start/stop, enumerate available
 // video capture devices, and manage VideoCaptureController's.
 // All functions are expected to be called from Browser::IO thread.
 // VideoCaptureManager will open OS dependent instances of VideoCaptureDevice.
 // A device can only be opened once.
 
 #ifndef CONTENT_BROWSER_RENDERER_HOST_MEDIA_VIDEO_CAPTURE_MANAGER_H_
 #define CONTENT_BROWSER_RENDERER_HOST_MEDIA_VIDEO_CAPTURE_MANAGER_H_
 
 #include <list>
 #include <map>
 
 #include "base/memory/ref_counted.h"
 #include "base/threading/thread.h"
 #include "content/browser/renderer_host/media/media_stream_provider.h"
 #include "content/common/content_export.h"
 #include "content/common/media/media_stream_options.h"
 #include "media/video/capture/video_capture_device.h"
 #include "media/video/capture/video_capture_types.h"
 
+class MockVideoCaptureManager;
 class VideoCaptureController;
 class VideoCaptureControllerEventHandler;
 
 namespace media_stream {
 
 // VideoCaptureManager opens/closes and start/stops video capture devices.
 class CONTENT_EXPORT VideoCaptureManager
     : public base::RefCountedThreadSafe<VideoCaptureManager>,
       public MediaStreamProvider {
  public:
@@ skipping 12 matching lines @@
   virtual void EnumerateDevices() OVERRIDE;
 
   virtual int Open(const StreamDeviceInfo& device) OVERRIDE;
 
   virtual void Close(int capture_session_id) OVERRIDE;
 
   // Functions used to start and stop media flow.
   // Start allocates the device and no other application can use the device
   // before Stop is called. Captured video frames will be delivered to
   // video_capture_receiver.
-  void Start(const media::VideoCaptureParams& capture_params,
+  virtual void Start(const media::VideoCaptureParams& capture_params,
              media::VideoCaptureDevice::EventHandler* video_capture_receiver);
 
   // Stops capture device referenced by |capture_session_id|. No more frames
   // will be delivered to the frame receiver, and |stopped_cb| will be called.
   // |stopped_cb| can be NULL.
-  void Stop(const media::VideoCaptureSessionId& capture_session_id,
+  virtual void Stop(const media::VideoCaptureSessionId& capture_session_id,
             base::Closure stopped_cb);
 
   // A capture device error has occurred for |capture_session_id|. The device
   // won't stream any more captured frames.
-  void Error(const media::VideoCaptureSessionId& capture_session_id);
+  virtual void Error(const media::VideoCaptureSessionId& capture_session_id);
 
   // Used by unit test to make sure a fake device is used instead of a real
   // video capture device. Due to timing requirements, the function must be
   // called before EnumerateDevices and Open.
   void UseFakeDevice();
   MessageLoop* GetMessageLoop();
 
   // Called by VideoCaptureHost to get a controller for |capture_params|.
   // The controller is returned via calling |added_cb|.
   void AddController(
       const media::VideoCaptureParams& capture_params,
       VideoCaptureControllerEventHandler* handler,
       base::Callback<void(VideoCaptureController*)> added_cb);
   // Called by VideoCaptureHost to remove the |controller|.
   void RemoveController(
       VideoCaptureController* controller,
       VideoCaptureControllerEventHandler* handler);
 
  private:
+  friend class ::MockVideoCaptureManager;
   friend class base::RefCountedThreadSafe<VideoCaptureManager>;
   virtual ~VideoCaptureManager();
 
   typedef std::list<VideoCaptureControllerEventHandler*> Handlers;
   struct Controller;
 
   // Called by the public functions, executed on vc_device_thread_.
   void OnEnumerateDevices();
   void OnOpen(int capture_session_id, const StreamDeviceInfo& device);
   void OnClose(int capture_session_id);
@@ skipping 53 matching lines @@
   // VideoCaptureDevice is one-to-one mapped to VideoCaptureController.
   typedef std::map<media::VideoCaptureDevice*, Controller*> Controllers;
   Controllers controllers_;
 
   DISALLOW_COPY_AND_ASSIGN(VideoCaptureManager);
 };
 
 }  // namespace media_stream
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_VIDEO_CAPTURE_MANAGER_H_