Add support for configuring the number of spatial/temporal layers for VP9 through a field trial.

webrtc/media/engine/fakewebrtccall.cc

 /*
  *  Copyright (c) 2015 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 148 matching lines @@
   return stats_;
 }
 
 void FakeVideoSendStream::ReconfigureVideoEncoder(
     const webrtc::VideoEncoderConfig& config) {
   encoder_config_ = config;
   if (config.encoder_specific_settings != NULL) {
     if (config_.encoder_settings.payload_name == "VP8") {
       vpx_settings_.vp8 = *reinterpret_cast<const webrtc::VideoCodecVP8*>(
                               config.encoder_specific_settings);
+      if (!config.streams.empty()) {
+        vpx_settings_.vp8.numberOfTemporalLayers = static_cast<unsigned char>(
+            config.streams.back().temporal_layer_thresholds_bps.size() + 1);
+      }
     } else if (config_.encoder_settings.payload_name == "VP9") {
       vpx_settings_.vp9 = *reinterpret_cast<const webrtc::VideoCodecVP9*>(
                               config.encoder_specific_settings);
+      if (!config.streams.empty()) {
+        vpx_settings_.vp9.numberOfTemporalLayers = static_cast<unsigned char>(
+            config.streams.back().temporal_layer_thresholds_bps.size() + 1);
+      }
     } else {
       ADD_FAILURE() << "Unsupported encoder payload: "
                     << config_.encoder_settings.payload_name;
     }
   }
   codec_settings_set_ = config.encoder_specific_settings != NULL;
 }
 
 webrtc::VideoCaptureInput* FakeVideoSendStream::Input() {
   return this;
@@ skipping 234 matching lines @@
 }
 
 void FakeCall::SignalNetworkState(webrtc::NetworkState state) {
   network_state_ = state;
 }
 
 void FakeCall::OnSentPacket(const rtc::SentPacket& sent_packet) {
   last_sent_packet_ = sent_packet;
 }
 }  // namespace cricket