Removes example code that isn't correctly wired up

chrome/app/mash/BUILD.gn

 # Copyright 2016 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("//services/service_manager/public/service_manifest.gni")
 
 source_set("mash") {
   sources = [
     "mash_runner.cc",
     "mash_runner.h",
   ]
   deps = [
     "//ash/resources",
     "//base:i18n",
     "//components/tracing:startup_tracing",
     "//content/public/common",
     "//mash/package",
+    "//mash/session/public/interfaces:constants",
     "//services/catalog/public/interfaces",
     "//services/service_manager",
     "//services/service_manager/background:lib",
     "//services/service_manager/public/cpp",
     "//services/service_manager/public/cpp/standalone_service",
     "//services/service_manager/public/interfaces",
     "//services/service_manager/runner:init",
     "//services/service_manager/runner/common",
     "//services/service_manager/runner/host:lib",
     "//services/service_manager/standalone:lib",
@@ skipping 47 matching lines @@
 
 service_manifest("browser_manifest") {
   name = "content_browser"
   source = "${root_out_dir}/Packages/chrome_content_browser/manifest.json"
   output_name = "chrome_mash_content_browser"
   deps = [
     "//chrome/app:chrome_content_browser_manifest",
   ]
   overlays = [ "chrome_mash_content_browser_manifest_overlay.json" ]
 }