Add/remove surface references via MojoCompositorFrameSink.

services/ui/surfaces/gpu_compositor_frame_sink.h

Index: services/ui/surfaces/gpu_compositor_frame_sink.h
diff --git a/services/ui/surfaces/gpu_compositor_frame_sink.h b/services/ui/surfaces/gpu_compositor_frame_sink.h
index f32b9f7da9a9f5bfbcbf96c7596dd057a6d0fd81..c704e93173c090db49725c5be7af903ee19afc8a 100644
--- a/services/ui/surfaces/gpu_compositor_frame_sink.h
+++ b/services/ui/surfaces/gpu_compositor_frame_sink.h
@@ -23,6 +23,7 @@
 #include "cc/surfaces/surface_factory_client.h"
 #include "cc/surfaces/surface_id.h"
 #include "cc/surfaces/surface_id_allocator.h"
+#include "cc/surfaces/surface_reference.h"
 #include "mojo/public/cpp/bindings/binding.h"
 
 namespace base {
@@ -60,6 +61,10 @@ class GpuCompositorFrameSink : public cc::mojom::MojoCompositorFrameSink,
   void SetNeedsBeginFrame(bool needs_begin_frame) override;
   void SubmitCompositorFrame(const cc::LocalFrameId& local_frame_id,
                              cc::CompositorFrame frame) override;
+  void AddSurfaceReferences(
+      const std::vector<cc::SurfaceReference>& references) override;
+  void RemoveSurfaceReferences(
+      const std::vector<cc::SurfaceReference>& references) override;
 
   // cc::mojom::MojoCompositorFrameSinkPrivate:
   void AddChildFrameSink(const cc::FrameSinkId& child_frame_sink_id) override;