WIP: move OffscreenCanvas into new display compositor

components/display_compositor/gpu_offscreen_compositor_frame_sink.cc

Index: components/display_compositor/gpu_offscreen_compositor_frame_sink.cc
diff --git a/components/display_compositor/gpu_offscreen_compositor_frame_sink.cc b/components/display_compositor/gpu_offscreen_compositor_frame_sink.cc
index 26312dff3bba52310a787a7d9843064ceea5d9fc..28d1bb2257cc65aa25ee765c881f38e73c1a433d 100644
--- a/components/display_compositor/gpu_offscreen_compositor_frame_sink.cc
+++ b/components/display_compositor/gpu_offscreen_compositor_frame_sink.cc
@@ -14,16 +14,17 @@ GpuOffscreenCompositorFrameSink::GpuOffscreenCompositorFrameSink(
     cc::mojom::MojoCompositorFrameSinkPrivateRequest
         compositor_frame_sink_private_request,
     cc::mojom::MojoCompositorFrameSinkClientPtr client)
-    : GpuCompositorFrameSink(delegate,
-                             base::MakeUnique<cc::CompositorFrameSinkSupport>(
-                                 this,
-                                 surface_manager,
-                                 frame_sink_id,
-                                 false /* is_root */,
-                                 true /* handles_frame_sink_id_invalidation */,
-                                 true /* needs_sync_points */),
-                             std::move(compositor_frame_sink_private_request),
-                             std::move(client)),
+    : GpuCompositorFrameSinkBase(
+          delegate,
+          base::MakeUnique<cc::CompositorFrameSinkSupport>(
+              this,
+              surface_manager,
+              frame_sink_id,
+              false /* is_root */,
+              true /* handles_frame_sink_id_invalidation */,
+              true /* needs_sync_points */),
+          std::move(compositor_frame_sink_private_request),
+          std::move(client)),
       binding_(this, std::move(request)) {
   binding_.set_connection_error_handler(
       base::Bind(&GpuOffscreenCompositorFrameSink::OnClientConnectionLost,