support video device enumeration from renderer process.

content/renderer/media/media_stream_dispatcher_eventhandler.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_RENDERER_MEDIA_MEDIA_STREAM_DISPATCHER_EVENTHANDLER_H_
 #define CONTENT_RENDERER_MEDIA_MEDIA_STREAM_DISPATCHER_EVENTHANDLER_H_
 
 #include <string>
 
 #include "content/common/content_export.h"
@@ skipping 15 matching lines @@
   // An error have occurred on a video device. This is called if a runtime
   // error occurs.
   virtual void OnVideoDeviceFailed(const std::string& label,
                                    int index) = 0;
 
   // An error have occurred on an audio device. This is called if a runtime
   // error occurs.
   virtual void OnAudioDeviceFailed(const std::string& label,
                                    int index) = 0;
 
+  // A new list of devices have been enumerated.
+  virtual void OnDevicesEnumerated(
+      int request_id,
+      const media_stream::StreamDeviceInfoArray& device_array) = 0;
+
+  // Failed to enumerate devices.
+  virtual void OnDevicesEnumerationFailed(int request_id) = 0;
+
+  // A device has been opened.
+  virtual void OnDeviceOpened(
+      int request_id,
+      const std::string& label,
+      const media_stream::StreamDeviceInfo& device_info) = 0;
+
+  // Failed to open the device.
+  virtual void OnDeviceOpenFailed(int request_id) = 0;
+
  protected:
   virtual ~MediaStreamDispatcherEventHandler();
 };
 
 #endif  // CONTENT_RENDERER_MEDIA_MEDIA_STREAM_DISPATCHER_EVENTHANDLER_H_