Reduce SurfaceIdAllocator usage and tie SurfaceFactory to a single FrameSinkId

services/ui/ws/server_window_surface.h

Index: services/ui/ws/server_window_surface.h
diff --git a/services/ui/ws/server_window_surface.h b/services/ui/ws/server_window_surface.h
index a0297f87d3363a5663f0b532f88faab9ff6deb5b..258a433462c784fb8da004eaf3a1583b995f62a1 100644
--- a/services/ui/ws/server_window_surface.h
+++ b/services/ui/ws/server_window_surface.h
@@ -9,6 +9,7 @@
 
 #include "base/macros.h"
 #include "cc/ipc/compositor_frame.mojom.h"
+#include "cc/surfaces/frame_sink_id.h"
 #include "cc/surfaces/surface_factory.h"
 #include "cc/surfaces/surface_factory_client.h"
 #include "cc/surfaces/surface_id.h"
@@ -60,6 +61,8 @@ class ServerWindowSurface : public mojom::Surface,
   void ReturnResources(const cc::ReturnedResourceArray& resources) override;
   void SetBeginFrameSource(cc::BeginFrameSource* begin_frame_source) override;
 
+  const cc::FrameSinkId frame_sink_id_;
+
   ServerWindowSurfaceManager* manager_;  // Owns this.
 
   gfx::Size last_submitted_frame_size_;