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

media/gpu/vp8_picture.h

Index: media/gpu/vp8_picture.h
diff --git a/media/gpu/vp8_picture.h b/media/gpu/vp8_picture.h
index 164cf0a2c7e2259984603cf4d6936b4cb4980fed..f31a344bd67ce91211842e3eaa729796452dff22 100644
--- a/media/gpu/vp8_picture.h
+++ b/media/gpu/vp8_picture.h
@@ -7,6 +7,7 @@
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
+#include "ui/gfx/geometry/rect.h"
 
 namespace media {
 
@@ -20,6 +21,9 @@ class VP8Picture : public base::RefCounted<VP8Picture> {
   virtual V4L2VP8Picture* AsV4L2VP8Picture();
   virtual VaapiVP8Picture* AsVaapiVP8Picture();
 
+  // The visible size of picture.
+  gfx::Rect visible_rect;
+
  protected:
   friend class base::RefCounted<VP8Picture>;
   virtual ~VP8Picture();