Make sure WebRTC works without libvpx VP9 support.

webrtc/modules/video_coding/codecs/vp9/vp9_impl.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 29 matching lines @@
 #else
   // For smaller resolutions, use lower speed setting (get some coding gain at
   // the cost of increased encoding complexity).
   if (width * height <= 352 * 288)
     return 5;
   else
     return 7;
 #endif
 }
 
+bool VP9Encoder::IsSupported() {
+  return true;
+}
+
 VP9Encoder* VP9Encoder::Create() {
   return new VP9EncoderImpl();
 }
 
 void VP9EncoderImpl::EncoderOutputCodedPacketCallback(vpx_codec_cx_pkt* pkt,
                                                       void* user_data) {
   VP9EncoderImpl* enc = static_cast<VP9EncoderImpl*>(user_data);
   enc->GetEncodedLayerFrame(pkt);
 }
 
@@ skipping 753 matching lines @@
 int VP9EncoderImpl::RegisterEncodeCompleteCallback(
     EncodedImageCallback* callback) {
   encoded_complete_callback_ = callback;
   return WEBRTC_VIDEO_CODEC_OK;
 }
 
 const char* VP9EncoderImpl::ImplementationName() const {
   return "libvpx";
 }
 
+bool VP9Decoder::IsSupported() {
+  return true;
+}
+
 VP9Decoder* VP9Decoder::Create() {
   return new VP9DecoderImpl();
 }
 
 VP9DecoderImpl::VP9DecoderImpl()
     : decode_complete_callback_(NULL),
       inited_(false),
       decoder_(NULL),
       key_frame_required_(true) {
   memset(&codec_, 0, sizeof(codec_));
@@ skipping 147 matching lines @@
   frame_buffer_pool_.ClearPool();
   inited_ = false;
   return WEBRTC_VIDEO_CODEC_OK;
 }
 
 const char* VP9DecoderImpl::ImplementationName() const {
   return "libvpx";
 }
 
 }  // namespace webrtc