support video device enumeration from renderer process.

content/browser/renderer_host/media/media_stream_dispatcher_host.h

Index: content/browser/renderer_host/media/media_stream_dispatcher_host.h
===================================================================
--- content/browser/renderer_host/media/media_stream_dispatcher_host.h	(revision 109718)
+++ content/browser/renderer_host/media/media_stream_dispatcher_host.h	(working copy)
@@ -41,6 +41,13 @@
   virtual void AudioDeviceFailed(const std::string& label, int index);
   virtual void VideoDeviceFailed(const std::string& label, int index);
 
+  virtual void VideoDevicesEnumerated(const std::string& label,
+                                      const StreamDeviceInfoArray& devices);
+  virtual void VideoDevicesEnumerationFailed(const std::string& label);
+  virtual void VideoDeviceOpened(const std::string& label,
+                                 const StreamDeviceInfo& video_device);
+  virtual void VideoDeviceOpenFailed(const std::string& label);
+
   // BrowserMessageFilter implementation.
   virtual bool OnMessageReceived(const IPC::Message& message,
                                  bool* message_was_ok);
@@ -56,6 +63,15 @@
 
   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();