V4L2SVDA/VAAPIVDA: use visible size from decoder and pass to client

media/gpu/vp8_decoder.cc

 // Copyright 2015 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 "media/gpu/vp8_decoder.h"
 #include "media/base/limits.h"
 
 namespace media {
 
 VP8Decoder::VP8Accelerator::VP8Accelerator() {}
@@ skipping 167 matching lines @@
   curr_frame_hdr_ = nullptr;
   curr_frame_start_ = nullptr;
   frame_size_ = 0;
   return true;
 }
 
 gfx::Size VP8Decoder::GetPicSize() const {
   return pic_size_;
 }
 
+gfx::Rect VP8Decoder::GetVisibleRect() const {
+  return gfx::Rect(pic_size_);
+}
+
 size_t VP8Decoder::GetRequiredNumOfPictures() const {
   const size_t kVP8NumFramesActive = 4;
   const size_t kPicsInPipeline = limits::kMaxVideoFrames + 2;
   return kVP8NumFramesActive + kPicsInPipeline;
 }
 
 }  // namespace media