mandoline: write this after lunch.

components/font_service/BUILD.gn

 # Copyright 2015 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("//mojo/public/mojo_application.gni")
 
 source_set("lib") {
   sources = [
     "font_service_app.cc",
     "font_service_app.h",
   ]
 
   deps = [
     "//base",
     "//components/font_service/public/interfaces",
     "//mojo/application/public/cpp",
     "//mojo/common:common_base",
     "//mojo/platform_handle",
     "//mojo/public/cpp/bindings",
+    "//mojo/services/tracing/public/cpp",
   ]
 
   public_deps = [
     "//skia",
   ]
 }
 
 mojo_native_application("font_service") {
   sources = [
     "main.cc",
   ]
 
   deps = [
     ":lib",
     "//base",
     "//mojo/application/public/cpp",
     "//mojo/common",
     "//mojo/common:common_base",
     "//mojo/public/cpp/bindings:callback",
   ]
 }