support video device enumeration from renderer process.

content/browser/renderer_host/media/media_stream_dispatcher_host.h

 // Copyright (c) 2011 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 CONTENT_BROWSER_RENDERER_HOST_MEDIA_MEDIA_STREAM_DISPATCHER_HOST_H_
 #define CONTENT_BROWSER_RENDERER_HOST_MEDIA_MEDIA_STREAM_DISPATCHER_HOST_H_
 
 #include <map>
 #include <string>
 #include <utility>
@@ skipping 24 matching lines @@
   // MediaStreamRequester implementation.
   virtual void StreamGenerated(
       const std::string& label,
       const StreamDeviceInfoArray& audio_devices,
       const StreamDeviceInfoArray& video_devices) OVERRIDE;
 
   virtual void StreamGenerationFailed(const std::string& label) OVERRIDE;
   virtual void AudioDeviceFailed(const std::string& label, int index) OVERRIDE;
   virtual void VideoDeviceFailed(const std::string& label, int index) OVERRIDE;
 
+  virtual void VideoDevicesEnumerated(const std::string& label,
+                                      const StreamDeviceInfoArray& devices);
+  virtual void VideoDevicesEnumerationFailed(const std::string& label);
+  virtual void VideoDeviceOpened(const std::string& label,

[mflodman_chromium_OOO, 2011/11/29 02:30:56]

Q: Since we'll support audio in the future(?), what do you think about naming
this DeviceOpened and add MediaStreamType as a parameter?
Same for the calls below, IPC messages and MediaStreamManager.

[wjia(left Chromium), 2011/11/30 00:14:23]

Done. I thought the first step is to make video work. Then expand it to audio.
Since you are asking, these two steps are merged.

+                                 const StreamDeviceInfo& video_device);
+  virtual void VideoDeviceOpenFailed(const std::string& label);
+
   // BrowserMessageFilter implementation.
   virtual bool OnMessageReceived(const IPC::Message& message,
                                  bool* message_was_ok) OVERRIDE;
   virtual void OnChannelClosing() OVERRIDE;
 
  private:
   friend class MockMediaStreamDispatcherHost;
 
   void OnGenerateStream(int render_view_id,
                         int page_request_id,
                         const StreamOptions& components,
                         const std::string& security_origin);
 
   void OnStopGeneratedStream(int render_view_id, const std::string& label);
 
+  void OnEnumerateVideoDevices(int render_view_id,
+                               int page_request_id,
+                               const std::string& security_origin);
+
+  void OnOpenVideoDevice(int render_view_id,
+                         int page_request_id,
+                         const std::string& device_id,
+                         const std::string& security_origin);
+
   // Returns the media stream manager to forward events to,
   // creating one if needed.
   MediaStreamManager* manager();
 
   const content::ResourceContext* resource_context_;
   int render_process_id_;
 
   struct StreamRequest;
   typedef std::map<std::string, StreamRequest> StreamMap;
   // Streams generated for this host.
   StreamMap streams_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaStreamDispatcherHost);
 };
 
 }  // namespace media_stream
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_MEDIA_STREAM_DISPATCHER_HOST_H_