Move enable_app_list to a buildflag.

chrome/app/resources/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/chrome_build.gni")
+import("//chrome/common/features.gni")
 import("//tools/grit/grit_rule.gni")
 
 grit("locale_settings") {
   source = "locale_settings.grd"
   use_qualified_include = true
+  defines = chrome_grit_defines
   output_dir = "$root_gen_dir/chrome"
   outputs = [
     "grit/locale_settings.h",
     "locale_settings_am.pak",
     "locale_settings_ar.pak",
     "locale_settings_bg.pak",
     "locale_settings_bn.pak",
     "locale_settings_ca.pak",
     "locale_settings_cs.pak",
     "locale_settings_da.pak",
@@ skipping 56 matching lines @@
     if (is_chrome_branded) {
       source = "locale_settings_google_chromeos.grd"
     } else {
       source = "locale_settings_chromiumos.grd"
     }
   } else if (is_posix) {
     # All other posix systems just use the Linux one.
     source = "locale_settings_linux.grd"
   }
 
+  defines = chrome_grit_defines
   use_qualified_include = true
   outputs = [
     "grit/platform_locale_settings.h",
     "platform_locale_settings_am.pak",
     "platform_locale_settings_ar.pak",
     "platform_locale_settings_bg.pak",
     "platform_locale_settings_bn.pak",
     "platform_locale_settings_ca.pak",
     "platform_locale_settings_cs.pak",
     "platform_locale_settings_da.pak",
@@ skipping 41 matching lines @@
     "platform_locale_settings_th.pak",
     "platform_locale_settings_tr.pak",
     "platform_locale_settings_uk.pak",
     "platform_locale_settings_vi.pak",
     "platform_locale_settings_zh-CN.pak",
     "platform_locale_settings_zh-TW.pak",
   ]
 
   output_dir = "$root_gen_dir/chrome"
 }