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

media/gpu/vp8_decoder.h

 // 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.
 
 #ifndef MEDIA_GPU_VP8_DECODER_H_
 #define MEDIA_GPU_VP8_DECODER_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 54 matching lines @@
 
   VP8Decoder(VP8Accelerator* accelerator);
   ~VP8Decoder() override;
 
   // AcceleratedVideoDecoder implementation.
   bool Flush() override WARN_UNUSED_RESULT;
   void Reset() override;
   void SetStream(const uint8_t* ptr, size_t size) override;
   DecodeResult Decode() override WARN_UNUSED_RESULT;
   gfx::Size GetPicSize() const override;
+  gfx::Rect GetVisibleRect() const override;
   size_t GetRequiredNumOfPictures() const override;
 
  private:
   bool DecodeAndOutputCurrentFrame();
   void RefreshReferenceFrames();
 
   enum State {
     kNeedStreamMetadata,  // After initialization, need a keyframe.
     kDecoding,            // Ready to decode from any point.
     kAfterReset,          // After Reset(), need a resume point.
@@ skipping 18 matching lines @@
   int vertical_scale_;
 
   VP8Accelerator* accelerator_;
 
   DISALLOW_COPY_AND_ASSIGN(VP8Decoder);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_GPU_VP8_DECODER_H_