Add missing header files to GN files

services/ui/public/cpp/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("//build/config/ui.gni")
 
 # This is the public target. It contains only the public headers. The
 # implementation (and private haders) are in 'internal'.
 source_set("cpp") {
   sources = [
@@ skipping 37 matching lines @@
 source_set("internal") {
   # This target is an implementation detail and is intended only to be used by
   # the 'cpp' target.
   visibility = [
     ":cpp",
     "//services/ui/demo:lib",
   ]
 
   sources = [
     "client_compositor_frame_sink.cc",
+    "client_compositor_frame_sink.h",
     "property_type_converters.cc",
     "raster_thread_helper.cc",
   ]
 
   deps = [
     "//base",
     "//cc",
     "//cc/surfaces",
     "//cc/surfaces:surface_id",
     "//mojo/public/cpp/bindings",
@@ skipping 11 matching lines @@
   data_deps = [
     "//services/ui",
   ]
 
   defines = [ "GL_GLEXT_PROTOTYPES" ]
 
   if (use_ozone) {
     deps += [ "//ui/ozone" ]
   }
 }