First cut at "content handling" support in Mojo.

mojo/service_manager/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.
 
 # GYP version: mojo.gyp:mojo_service_manager
 component("service_manager") {
   output_name = "mojo_service_manager"
   sources = [
     "background_shell_service_loader.cc",
     "background_shell_service_loader.h",
+    "service_loader.cc",
     "service_loader.h",
     "service_manager.cc",
     "service_manager.h",
     "service_manager_export.h",
   ]
 
   defines = [ "MOJO_SERVICE_MANAGER_IMPLEMENTATION" ]
 
   deps = [
     "//base",
     "//base/third_party/dynamic_annotations",
     "//net",
     "//url",
     "//mojo/common",
     "//mojo/environment:chromium",
     "//mojo/public/interfaces/application:application",
+    "//mojo/services/public/interfaces/content_handler:content_handler",
+    "//mojo/services/public/interfaces/network:network",
     "//mojo/system",
   ]
 
   forward_dependent_configs_from = [
     "//mojo/public/interfaces/application:application",
   ]
 }