Add/remove surface references via MojoCompositorFrameSink.

services/ui/surfaces/gpu_compositor_frame_sink.cc

Index: services/ui/surfaces/gpu_compositor_frame_sink.cc
diff --git a/services/ui/surfaces/gpu_compositor_frame_sink.cc b/services/ui/surfaces/gpu_compositor_frame_sink.cc
index 92e2ec05c6b60dc57b6fe2063c6f7f8cab3798a1..4d0371a7c4d2037fa38a4da05d0002aa5d2a042c 100644
--- a/services/ui/surfaces/gpu_compositor_frame_sink.cc
+++ b/services/ui/surfaces/gpu_compositor_frame_sink.cc
@@ -97,6 +97,18 @@ void GpuCompositorFrameSink::SubmitCompositorFrame(
   }
 }
 
+void GpuCompositorFrameSink::AddSurfaceReferences(
+    const std::vector<cc::SurfaceReference>& references) {
+  for (auto& ref : references)
+    display_compositor_->AddSurfaceReference(ref);
+}
+
+void GpuCompositorFrameSink::RemoveSurfaceReferences(
+    const std::vector<cc::SurfaceReference>& references) {
+  for (auto& ref : references)
+    display_compositor_->RemoveSurfaceReference(ref);
+}
+
 void GpuCompositorFrameSink::DidReceiveCompositorFrameAck() {
   if (!client_)
     return;