Add extensions code to use common updater in components/update_client/

extensions/browser/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/crypto.gni")
 import("//build/config/features.gni")
 import("//extensions/extensions.gni")
 
 # GYP version: extensions/extensions.gyp:extensions_browser
 source_set("browser") {
   sources = []
 
   deps = [
     "//base:i18n",
     "//components/guest_view/browser",
     "//components/keyed_service/content",
     "//components/keyed_service/core",
     "//components/pref_registry",
     "//components/sessions",
     "//components/ui/zoom",
+    "//components/update_client",
+    "//components/version_info",
     "//components/web_cache/browser",
     "//components/web_modal",
     "//content/public/browser",
     "//crypto:platform",
     "//extensions/common",
     "//extensions/common/api",
     "//extensions/common/api:api_registration",
     "//extensions/strings",
     "//google_apis",
     "//skia",
@@ skipping 65 matching lines @@
           win_or_mac_sources = rebase_path(
                   extensions_gypi_values.extensions_browser_sources_win_or_mac,
                   ".",
                   "//extensions")
           sources += win_or_mac_sources
         }
       }
     }
   }
 }