Add missing //extensions/ deps for app_shim.

chrome/browser/apps/app_shim/BUILD.gn

 # Copyright 2015 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.
 
 # This is the part of the Chrome browser process responsible for launching and
 # communicating with app_shim processes on Mac.
 source_set("app_shim") {
   sources = [
     "app_shim_handler_mac.cc",
     "app_shim_handler_mac.h",
     "app_shim_host_mac.cc",
     "app_shim_host_mac.h",
     "app_shim_host_manager_mac.h",
     "app_shim_host_manager_mac.mm",
     "extension_app_shim_handler_mac.cc",
     "extension_app_shim_handler_mac.h",
     "unix_domain_socket_acceptor.cc",
     "unix_domain_socket_acceptor.h",
   ]
 
   deps = [
     "//content/public/browser",
     "//content/public/common",
+    "//extensions/browser",
+    "//extensions/common",
   ]
 }