MojoCompositorFrameSinkPrivate should support copy requests

components/display_compositor/gpu_compositor_frame_sink.cc

Index: components/display_compositor/gpu_compositor_frame_sink.cc
diff --git a/components/display_compositor/gpu_compositor_frame_sink.cc b/components/display_compositor/gpu_compositor_frame_sink.cc
index ac1584bc911155da467f1ed27e6918a6d92d9ab5..c41208926f66fdc2eb078ede5af2c5efbc7a1867 100644
--- a/components/display_compositor/gpu_compositor_frame_sink.cc
+++ b/components/display_compositor/gpu_compositor_frame_sink.cc
@@ -95,4 +95,11 @@ void GpuCompositorFrameSink::OnPrivateConnectionLost() {
                                      client_connection_lost_);
 }
 
+void GpuCompositorFrameSink::RequestCopyOfSurface(
+    std::unique_ptr<cc::CopyOutputRequest> request,
+    const RequestCopyOfSurfaceCallback& callback) {
+  request->set_result_callback(callback);
+  support_->RequestCopyOfSurface(std::move(request));
+}
+
 }  // namespace display_compositor