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

media/gpu/vp9_decoder.cc

Index: media/gpu/vp9_decoder.cc
diff --git a/media/gpu/vp9_decoder.cc b/media/gpu/vp9_decoder.cc
index b24f2466846e28485dd17b23372c2a57e0deb302..4d2295724013ae89004d7a4a19e619da466f1fdc 100644
--- a/media/gpu/vp9_decoder.cc
+++ b/media/gpu/vp9_decoder.cc
@@ -112,6 +112,15 @@ VP9Decoder::DecodeResult VP9Decoder::Decode() {
                            curr_frame_hdr_->frame_height);
     DCHECK(!new_pic_size.IsEmpty());
 
+    gfx::Rect new_render_rect(curr_frame_hdr_->render_width,
+                              curr_frame_hdr_->render_height);
+    // Due to specification render size should be set as not larger than frame
+    // size, or set as frame size if render_and_frame_size_different == 0. For
+    // safety we check the validity of render size or leave it as (0, 0).
+    if (!gfx::Rect(new_pic_size).Contains(new_render_rect))
+      new_render_rect = gfx::Rect();
+    DVLOG(1) << "Render resolution: " << new_render_rect.ToString();
+
     if (new_pic_size != pic_size_) {
       DVLOG(1) << "New resolution: " << new_pic_size.ToString();
 
@@ -138,6 +147,7 @@ VP9Decoder::DecodeResult VP9Decoder::Decode() {
     if (!pic)
       return kRanOutOfSurfaces;
 
+    pic->visible_rect = new_render_rect;
     pic->frame_hdr.reset(curr_frame_hdr_.release());
 
     if (!DecodeAndOutputPicture(pic)) {