Add/remove surface references via MojoCompositorFrameSink.

cc/surfaces/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//cc/cc.gni")
 
 cc_source_set("surface_id") {
   sources = [
     "frame_sink_id.cc",
     "frame_sink_id.h",
     "local_frame_id.cc",
     "local_frame_id.h",
     "surface_id.cc",
     "surface_id.h",
+    "surface_reference.cc",
+    "surface_reference.h",
     "surface_sequence.h",
     "surface_sequence_generator.cc",
     "surface_sequence_generator.h",
   ]
 
   deps = [
     "//base",
   ]
 }
 
@@ skipping 37 matching lines @@
     "//base/third_party/dynamic_annotations",
     "//cc",
     "//gpu/command_buffer/client:gles2_interface",
     "//gpu/command_buffer/common",
     "//skia",
     "//ui/events:events_base",
     "//ui/gfx",
     "//ui/gfx/geometry",
   ]
 }