Removed SSRC knowledge from ViEEncoder.

webrtc/modules/video_coding/video_coding_impl.cc

 /*
  *  Copyright (c) 2012 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.
  */
 
@@ skipping 134 matching lines @@
       sender_.SetVideoProtection(videoProtection);
     return receiver_.SetVideoProtection(videoProtection, enable);
   }
 
   int32_t AddVideoFrame(const VideoFrame& videoFrame,
                         const VideoContentMetrics* contentMetrics,
                         const CodecSpecificInfo* codecSpecificInfo) override {
     return sender_.AddVideoFrame(videoFrame, contentMetrics, codecSpecificInfo);
   }
 
-  int32_t IntraFrameRequest(int stream_index) override {
+  int32_t IntraFrameRequest(size_t stream_index) override {
     return sender_.IntraFrameRequest(stream_index);
   }
 
   int32_t EnableFrameDropper(bool enable) override {
     return sender_.EnableFrameDropper(enable);
   }
 
   void SuspendBelowMinBitrate() override {
     return sender_.SuspendBelowMinBitrate();
   }
@@ skipping 153 matching lines @@
     NackSender* nack_sender,
     KeyFrameRequestSender* keyframe_request_sender) {
   assert(clock);
   assert(event_factory);
   return new VideoCodingModuleImpl(clock, event_factory, nullptr, nullptr,
                                    nack_sender, keyframe_request_sender,
                                    nullptr);
 }
 
 }  // namespace webrtc