Update I420Buffer to new VideoFrameBuffer interface

webrtc/examples/peerconnection/client/linux/main_wnd.cc

 /*
  *  Copyright 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 505 matching lines @@
   width_ = width;
   height_ = height;
   image_.reset(new uint8_t[width * height * 4]);
   gdk_threads_leave();
 }
 
 void GtkMainWnd::VideoRenderer::OnFrame(
     const webrtc::VideoFrame& video_frame) {
   gdk_threads_enter();
 
-  rtc::scoped_refptr<webrtc::VideoFrameBuffer> buffer(
-      video_frame.video_frame_buffer());
+  rtc::scoped_refptr<webrtc::I420BufferInterface> buffer(
+      video_frame.video_frame_buffer()->ToI420());
   if (video_frame.rotation() != webrtc::kVideoRotation_0) {
     buffer = webrtc::I420Buffer::Rotate(*buffer, video_frame.rotation());
   }
   SetSize(buffer->width(), buffer->height());
 
   // The order in the name of libyuv::I420To(ABGR,RGBA) is ambiguous because
   // it doesn't tell you if it is referring to how it is laid out in memory as
   // bytes or if endiannes is taken into account.
   // This was supposed to be a call to libyuv::I420ToRGBA but it was resulting
   // in a reddish video output (see https://bugs.webrtc.org/6857) because it
   // was producing an unexpected byte order (ABGR, byte swapped).
   libyuv::I420ToABGR(buffer->DataY(), buffer->StrideY(),
                      buffer->DataU(), buffer->StrideU(),
                      buffer->DataV(), buffer->StrideV(),
                      image_.get(), width_ * 4,
                      buffer->width(), buffer->height());
 
   gdk_threads_leave();
 
   g_idle_add(Redraw, main_wnd_);
 }