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

media/gpu/accelerated_video_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_ACCELERATED_VIDEO_DECODER_H_
 #define MEDIA_GPU_ACCELERATED_VIDEO_DECODER_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include "base/macros.h"
 #include "media/gpu/media_gpu_export.h"
+#include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/geometry/size.h"
 
 namespace media {
 
 // An AcceleratedVideoDecoder is a video decoder that requires support from an
 // external accelerator (typically a hardware accelerator) to partially offload
 // the decode process after parsing stream headers, and performing reference
 // frame and state management.
 class MEDIA_GPU_EXPORT AcceleratedVideoDecoder {
  public:
@@ skipping 27 matching lines @@
 
   // Try to decode more of the stream, returning decoded frames asynchronously.
   // Return when more stream is needed, when we run out of free surfaces, when
   // we need a new set of them, or when an error occurs.
   virtual DecodeResult Decode() WARN_UNUSED_RESULT = 0;
 
   // Return dimensions/required number of output surfaces that client should
   // be ready to provide for the decoder to function properly.
   // To be used after Decode() returns kAllocateNewSurfaces.
   virtual gfx::Size GetPicSize() const = 0;
+  virtual gfx::Rect GetVisibleRect() const = 0;
   virtual size_t GetRequiredNumOfPictures() const = 0;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(AcceleratedVideoDecoder);
 };
 
 }  //  namespace media
 
 #endif  // MEDIA_GPU_ACCELERATED_VIDEO_DECODER_H_