mojo: Use ContentHandlers to bundle multiple Applications into a module.

components/core_services/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("//build/config/ui.gni")
 import("//third_party/mojo/src/mojo/public/mojo_application.gni")
 import("//testing/test.gni")
 
 # core_services should be thought of as a bundle of many of the services which
 # we ship with.
 mojo_native_application("core_services") {
   sources = [
     "core_services_application_delegate.cc",
     "main.cc",
   ]
 
   deps = [
     "//base",
     "//components/clipboard:lib",
     "//mojo/application",
     "//mojo/common",
     "//mojo/environment:chromium",
     "//third_party/mojo/src/mojo/public/interfaces/application",
     "//third_party/mojo/src/mojo/public/cpp/bindings:bindings",
+    "//third_party/mojo_services/src/content_handler/public/interfaces",
   ]
 }