Add browser_extensions to GN build.

chrome/browser/ui/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("//build/config/ui.gni")
 
 gypi_values = exec_script(
     "//build/gypi_to_gn.py",
@@ skipping 64 matching lines @@
 
   forward_dependent_configs_from = [
     "//components/dom_distiller/core",
     "//sync",
   ]
 
   if (!is_ios) {
     sources += rebase_path(gypi_values.chrome_browser_ui_non_ios_sources,
                            ".", "//chrome")
     deps += [
+      "//chrome/browser/extensions",
       "//chrome/browser/performance_monitor",
       "//chrome/browser/ui/webui/omnibox:mojo_bindings",
       "//chrome/common/extensions/api:api",
       "//components/autofill/content/browser:risk_proto",
       "//mojo/system",
       "//net:net_with_v8",
       "//third_party/adobe/flash:flapper_version_h",
       "//third_party/expat",
       "//third_party/hunspell",
       "//third_party/leveldatabase",
       "//third_party/npapi",
       "//third_party/re2",
       "//ui/compositor",
       "//ui/surface",
       "//v8",
       "//webkit:resources",
       "//webkit/browser:storage",
       "//webkit/common",
       "//webkit/common:storage",
-      #'browser_extensions',  TODO(GYP)
       #'debugger',  TODO(GYP)
       #'installer_util',  TODO(GYP)
       #'../device/bluetooth/bluetooth.gyp:device_bluetooth',  TODO(GYP)
       #'../device/nfc/nfc.gyp:device_nfc',  TODO(GYP)
       #'../media/media.gyp:media',  TODO(GYP)
       #'../third_party/libjingle/libjingle.gyp:libjingle',  TODO(GYP)
       #'../ui/web_dialogs/web_dialogs.gyp:web_dialogs',  TODO(GYP)
     ]
     # TODO(GYP)
     #'defines': [
@@ skipping 297 matching lines @@
   }
   if (enable_service_discovery) {
     sources += rebase_path(
         gypi_values.chrome_browser_ui_service_discovery_sources,
         ".", "//chrome")
   }
   if (enable_spellcheck) {
     deps += [ "//third_party/hunspell" ]
   }
 }