Make sure WebRTC works without libvpx VP9 support.

webrtc/media/engine/webrtcvideoengine2.cc

 /*
  *  Copyright (c) 2014 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 11 matching lines @@
 #include "webrtc/base/trace_event.h"
 #include "webrtc/call.h"
 #include "webrtc/media/engine/constants.h"
 #include "webrtc/media/engine/simulcast.h"
 #include "webrtc/media/engine/webrtcmediaengine.h"
 #include "webrtc/media/engine/webrtcvideoencoderfactory.h"
 #include "webrtc/media/engine/webrtcvideoframe.h"
 #include "webrtc/media/engine/webrtcvoiceengine.h"
 #include "webrtc/modules/video_coding/codecs/h264/include/h264.h"
 #include "webrtc/modules/video_coding/codecs/vp8/simulcast_encoder_adapter.h"
+#include "webrtc/modules/video_coding/codecs/vp9/include/vp9.h"
 #include "webrtc/system_wrappers/include/field_trial.h"
 #include "webrtc/video_decoder.h"
 #include "webrtc/video_encoder.h"
 
 namespace cricket {
 namespace {
 
 // Wrap cricket::WebRtcVideoEncoderFactory as a webrtc::VideoEncoderFactory.
 class EncoderFactoryAdapter : public webrtc::VideoEncoderFactory {
  public:
@@ skipping 110 matching lines @@
   // A list of encoders that were created without being wrapped in a
   // SimulcastEncoderAdapter.
   std::vector<webrtc::VideoEncoder*> non_simulcast_encoders_;
 };
 
 bool CodecIsInternallySupported(const std::string& codec_name) {
   if (CodecNamesEq(codec_name, kVp8CodecName)) {
     return true;
   }
   if (CodecNamesEq(codec_name, kVp9CodecName)) {
-    return true;
+    return webrtc::VP9Encoder::IsSupported() &&
+           webrtc::VP9Decoder::IsSupported();
   }
   if (CodecNamesEq(codec_name, kH264CodecName)) {
     return webrtc::H264Encoder::IsSupported() &&
         webrtc::H264Decoder::IsSupported();
   }
   return false;
 }
 
 void AddDefaultFeedbackParams(VideoCodec* codec) {
   codec->AddFeedbackParam(FeedbackParam(kRtcpFbParamCcm, kRtcpFbCcmParamFir));
@@ skipping 2414 matching lines @@
         rtx_mapping[video_codecs[i].codec.id] !=
             fec_settings.red_payload_type) {
       video_codecs[i].rtx_payload_type = rtx_mapping[video_codecs[i].codec.id];
     }
   }
 
   return video_codecs;
 }
 
 }  // namespace cricket