media/gpu/test: Copy coded area of VideoFrame

This fixes a bug that CopyVideoFrame() copies by a visible size
only. The function should copy by coded size, otherwise a real
visible size is not copied when the visible area begins with
non-(0, 0) point.

Bug: None
Test: IPTest on atlas
Change-Id: I2412e6bcc72c7a5668e8dca15f126c2e16979976
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2000435Reviewed-by: David Staessens <dstaessens@chromium.org>
Commit-Queue: Hirokazu Honda <hiroh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#731793}

media/gpu/test/video_frame_helpers.cc

@@ -164,8 +164,8 @@ bool CopyVideoFrame(const VideoFrame* src_frame,
                         false);
   for (size_t i = 0; i < num_planes; ++i) {
     // |width| in libyuv::CopyPlane() is in bytes, not pixels.
-    gfx::Size plane_size = VideoFrame::PlaneSize(dst_frame->format(), i,
-                                                 dst_frame->natural_size());
+    gfx::Size plane_size =
+        VideoFrame::PlaneSize(dst_frame->format(), i, dst_frame->coded_size());
     libyuv::CopyPlane(
         src_frame->data(i), src_frame->layout().planes()[i].stride,
         dst_frame->data(i), dst_frame->layout().planes()[i].stride,