support video device enumeration from renderer process.

content/renderer/render_view_impl.cc

 // 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.
 
 #include "content/renderer/render_view_impl.h"
 
 #include <algorithm>
 #include <cmath>
 #include <string>
 #include <vector>
@@ skipping 419 matching lines @@
 
   OnSetRendererPrefs(renderer_prefs);
 
   host_window_ = parent_hwnd;
 
 #if defined(ENABLE_P2P_APIS)
   if (!p2p_socket_dispatcher_)
     p2p_socket_dispatcher_ = new content::P2PSocketDispatcher(this);
 #endif
 
+  if (!media_stream_dispatcher_)
+    media_stream_dispatcher_ = new MediaStreamDispatcher(this);
+
   new MHTMLGenerator(this);
 #if defined(OS_MACOSX)
   new TextInputClientObserver(this);
 #endif  // defined(OS_MACOSX)
 
   devtools_agent_ = new DevToolsAgent(this);
 
   renderer_accessibility_ = new RendererAccessibility(this);
 
   new IdleUserDetector(this);
@@ skipping 4462 matching lines @@
 bool RenderViewImpl::WebWidgetHandlesCompositorScheduling() const {
   return !!RenderThreadImpl::current()->compositor_thread();
 }
 
 void RenderViewImpl::OnJavaBridgeInit() {
   DCHECK(!java_bridge_dispatcher_.get());
 #if defined(ENABLE_JAVA_BRIDGE)
   java_bridge_dispatcher_.reset(new JavaBridgeDispatcher(this));
 #endif
 }