Pref service: expose all read-only PrefStores through Mojo

chrome/app/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")
 import("//chrome/common/features.gni")
 import("//ppapi/features/features.gni")
 import("//printing/features/features.gni")
 import("//services/catalog/public/tools/catalog.gni")
 import("//services/service_manager/public/service_manifest.gni")
@@ skipping 363 matching lines @@
   source =
       "//chrome/browser/chrome_content_packaged_services_manifest_overlay.json"
   packaged_services = chrome_packaged_services
   if (is_chromeos) {
     packaged_services += [ "//ash/mus:manifest" ]
   }
 }
 
 service_manifest("chrome_content_browser_manifest_overlay") {
   source = "//chrome/browser/chrome_content_browser_manifest_overlay.json"
+  packaged_services = [ "//chrome/browser:preferences2_manifest" ]
 }
 
 service_manifest("chrome_content_gpu_manifest_overlay") {
   source = "//chrome/browser/chrome_content_gpu_manifest_overlay.json"
 }
 
 service_manifest("chrome_content_plugin_manifest_overlay") {
   source = "//chrome/browser/chrome_content_plugin_manifest_overlay.json"
 }
 
@@ skipping 90 matching lines @@
           chrome_embedded_services +
           [ ":chrome_content_packaged_services_manifest_for_mash" ]
     }
   }
 
   catalog("catalog") {
     embedded_services = chrome_embedded_services +
                         [ ":chrome_content_packaged_services_manifest" ]
   }
 }