support video device enumeration from renderer process.

content/renderer/render_view_impl.h

Index: content/renderer/render_view_impl.h
===================================================================
--- content/renderer/render_view_impl.h	(revision 109718)
+++ content/renderer/render_view_impl.h	(working copy)
@@ -62,6 +62,7 @@
 class IntentsDispatcher;
 class JavaBridgeDispatcher;
 class LoadProgressTracker;
+class MediaStreamDispatcher;
 class MediaStreamImpl;
 class NotificationProvider;
 class PepperDeviceTest;
@@ -201,6 +202,10 @@
     return p2p_socket_dispatcher_;
   }
 
+  MediaStreamDispatcher* media_stream_dispatcher() {
+    return media_stream_dispatcher_;
+  }
+
   // Functions to add and remove observers for this object.
   void AddObserver(content::RenderViewObserver* observer);
   void RemoveObserver(content::RenderViewObserver* observer);
@@ -1135,6 +1140,9 @@
   // Device orientation dispatcher attached to this view; lazily initialized.
   DeviceOrientationDispatcher* device_orientation_dispatcher_;
 
+  // MediaStream dispatcher attached to this view; lazily initialized.
+  MediaStreamDispatcher* media_stream_dispatcher_;
+
   // MediaStreamImpl attached to this view; lazily initialized.
   scoped_refptr<MediaStreamImpl> media_stream_impl_;