WIP: move OffscreenCanvas into new display compositor

components/display_compositor/gpu_display_compositor_frame_sink.cc

Index: components/display_compositor/gpu_display_compositor_frame_sink.cc
diff --git a/components/display_compositor/gpu_display_compositor_frame_sink.cc b/components/display_compositor/gpu_display_compositor_frame_sink.cc
index 65b56b23090f5dc5447082438b968076c0ecb9a4..2963b387461f12e7e799ff8e5fc6c74827d32181 100644
--- a/components/display_compositor/gpu_display_compositor_frame_sink.cc
+++ b/components/display_compositor/gpu_display_compositor_frame_sink.cc
@@ -17,16 +17,17 @@ GpuDisplayCompositorFrameSink::GpuDisplayCompositorFrameSink(
         compositor_frame_sink_private_request,
     cc::mojom::MojoCompositorFrameSinkClientPtr client,
     cc::mojom::DisplayPrivateAssociatedRequest display_private_request)
-    : GpuCompositorFrameSink(delegate,
-                             base::MakeUnique<cc::CompositorFrameSinkSupport>(
-                                 this,
-                                 surface_manager,
-                                 frame_sink_id,
-                                 true /* 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,
+              true /* 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)),
       display_private_binding_(this, std::move(display_private_request)),
       display_begin_frame_source_(std::move(begin_frame_source)),