Enable passing receive stream ID to the decoder factory.

webrtc/media/engine/webrtcvideodecoderfactory.h

 /*
  *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #ifndef WEBRTC_MEDIA_ENGINE_WEBRTCVIDEODECODERFACTORY_H_
 #define WEBRTC_MEDIA_ENGINE_WEBRTCVIDEODECODERFACTORY_H_
 
 #include "webrtc/base/refcount.h"
 #include "webrtc/common_types.h"
 
 namespace webrtc {
 class VideoDecoder;
 }
 
 namespace cricket {
 
 class WebRtcVideoDecoderFactory {
  public:
+  // Some VideoDecoderFactories may choose to override this method for example
+  // to store the SSRC. Default behavior is just to call CreateVideoDecoder.
+  virtual webrtc::VideoDecoder* CreateVideoDecoderForSsrc(

[perkj_webrtc, 2016/06/10 13:46:39]

nit: Can you move this to below the existing CreateVideoDecoder and remove the
comments. They don't add any value. 

[sakal, 2016/06/14 13:28:44]

Done.

+      uint32_t ssrc,
+      webrtc::VideoCodecType type) {
+    return CreateVideoDecoder(type);
+  }
+
   // Caller takes the ownership of the returned object and it should be released
   // by calling DestroyVideoDecoder().
   virtual webrtc::VideoDecoder* CreateVideoDecoder(
       webrtc::VideoCodecType type) = 0;
   virtual ~WebRtcVideoDecoderFactory() {}
 
   virtual void DestroyVideoDecoder(webrtc::VideoDecoder* decoder) = 0;
 };
 
 }  // namespace cricket
 
 #endif  // WEBRTC_MEDIA_ENGINE_WEBRTCVIDEODECODERFACTORY_H_