Implement CancelUserMediaRequest for the browser part

content/browser/renderer_host/media/media_stream_manager.h

 // 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.
 
 // MediaStreamManager is used to open/enumerate media capture devices (video
 // supported now). Call flow:
 // 1. GenerateStream is called when a render process wants to use a capture
 //    device.
 // 2. MediaStreamManager will ask MediaStreamDeviceSettings for permission to
 //    use devices and for which device to use.
@@ skipping 67 matching lines @@
   // request is identified using |label|, which is pointing to an already
   // created std::string.
   void GenerateStream(MediaStreamRequester* requester, int render_process_id,
                       int render_view_id, const StreamOptions& options,
                       const GURL& security_origin, std::string* label);
 
   // Cancels all non-finished GenerateStream request, i.e. request for which
   // StreamGenerated hasn't been called.
   void CancelRequests(MediaStreamRequester* requester);
 
+  // Cancel generate stream.
+  void CancelGenerateStream(const std::string& label);
+
   // Closes generated stream.
   void StopGeneratedStream(const std::string& label);
 
   // Gets a list of devices of |type|.
   // The request is identified using |label|, which is pointing to a
   // std::string.
   void EnumerateDevices(MediaStreamRequester* requester,
                         int render_process_id,
                         int render_view_id,
                         MediaStreamType type,
@@ skipping 60 matching lines @@
   typedef std::map<std::string, DeviceRequest> DeviceRequests;
   DeviceRequests requests_;
   media::AudioManager* audio_manager_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaStreamManager);
 };
 
 }  // namespace media_stream
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_MEDIA_STREAM_MANAGER_H_