Tab Capture: Backing store readbacks to YV12 VideoFrames.

content/browser/renderer_host/render_widget_host_view_win.cc

Index: content/browser/renderer_host/render_widget_host_view_win.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_win.cc b/content/browser/renderer_host/render_widget_host_view_win.cc
index 0e3e081cc732bae8c38b33a7de2ad061aab2133c..35bd7085599594d7aaa9c6c7d784de6de2854e85 100644
--- a/content/browser/renderer_host/render_widget_host_view_win.cc
+++ b/content/browser/renderer_host/render_widget_host_view_win.cc
@@ -826,10 +826,23 @@ void RenderWidgetHostViewWin::CopyFromCompositingSurface(
     return;
 
   scoped_callback_runner.Release();
-  accelerated_surface_->AsyncCopyTo(
-      src_subrect,
-      dst_size,
-      callback);
+  accelerated_surface_->AsyncCopyTo(src_subrect, dst_size, callback);
+}
+
+void RenderWidgetHostViewWin::CopyFromCompositingSurfaceToVideoFrame(
+    const gfx::Rect& src_subrect,
+    const gfx::Size& dst_size,
+    const base::Callback<void(media::VideoFrame*)>& callback) {
+  base::ScopedClosureRunner scoped_callback_runner(
+      base::Bind(callback, media::VideoFrame::CreateEmptyFrame()));
+  if (!accelerated_surface_.get())
+    return;
+
+  if (dst_size.IsEmpty())
+    return;
+
+  scoped_callback_runner.Release();
+  accelerated_surface_->AsyncCopyToVideoFrame(src_subrect, dst_size, callback);
 }
 
 void RenderWidgetHostViewWin::SetBackground(const SkBitmap& background) {