Add VP9 decode support to the remoting client.

remoting/codec/video_encoder_vpx.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "remoting/codec/video_encoder_vpx.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/sys_info.h"
 #include "base/time/time.h"
@@ skipping 179 matching lines @@
   memset(image_.get(), 0, sizeof(vpx_image_t));
 
   image_->fmt = VPX_IMG_FMT_YV12;
 
   // libvpx seems to require both to be assigned.
   image_->d_w = size.width();
   image_->w = size.width();
   image_->d_h = size.height();
   image_->h = size.height();
 
+  // libvpx should derive this from|fmt| but currently has a bug:
+  // https://code.google.com/p/webm/issues/detail?id=627
+  image_->x_chroma_shift = 1;
+  image_->y_chroma_shift = 1;
+
   // Initialize active map.
   active_map_width_ = (image_->w + kMacroBlockSize - 1) / kMacroBlockSize;
   active_map_height_ = (image_->h + kMacroBlockSize - 1) / kMacroBlockSize;
   active_map_.reset(new uint8[active_map_width_ * active_map_height_]);
 
   // YUV image size is 1.5 times of a plane. Multiplication is performed first
   // to avoid rounding error.
   const int y_plane_size = image_->w * image_->h;
   const int uv_width = (image_->w + 1) / 2;
   const int uv_height = (image_->h + 1) / 2;
@@ skipping 97 matching lines @@
     uint8* map = active_map_.get() + top * active_map_width_;
     for (int y = top; y <= bottom; ++y) {
       for (int x = left; x <= right; ++x)
         map[x] = 1;
       map += active_map_width_;
     }
   }
 }
 
 }  // namespace remoting