Move enable_app_list to a buildflag.

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("//services/shell/public/service_manifest.gni")
 import("//tools/grit/grit_rule.gni")
 
 # This target is for dependency tracking for the command ID header.
@@ skipping 141 matching lines @@
         rebase_path(android_generated_java_resources, "java/res", ".")
     deps = [
       ":generated_resources",
     ]
   }
 }
 
 grit("google_chrome_strings") {
   source = "google_chrome_strings.grd"
   use_qualified_include = true
+  defines = chrome_grit_defines
   output_dir = "$root_gen_dir/chrome"
   outputs = [
     "grit/google_chrome_strings.h",
     "google_chrome_strings_am.pak",
     "google_chrome_strings_ar.pak",
     "google_chrome_strings_bg.pak",
     "google_chrome_strings_bn.pak",
     "google_chrome_strings_ca.pak",
     "google_chrome_strings_cs.pak",
     "google_chrome_strings_da.pak",
@@ skipping 43 matching lines @@
     "google_chrome_strings_vi.pak",
     "google_chrome_strings_zh-CN.pak",
     "google_chrome_strings_zh-TW.pak",
     "google_chrome_strings_fake-bidi.pak",
   ]
 }
 
 grit("chromium_strings") {
   source = "chromium_strings.grd"
   use_qualified_include = true
+  defines = chrome_grit_defines
   output_dir = "$root_gen_dir/chrome"
   outputs = [
     "grit/chromium_strings.h",
     "chromium_strings_am.pak",
     "chromium_strings_ar.pak",
     "chromium_strings_bg.pak",
     "chromium_strings_bn.pak",
     "chromium_strings_ca.pak",
     "chromium_strings_cs.pak",
     "chromium_strings_da.pak",
@@ skipping 157 matching lines @@
 
   group("service_manifests") {
     data_deps = [
       ":chrome_content_browser_manifest",
       ":chrome_content_gpu_manifest",
       ":chrome_content_renderer_manifest",
       ":chrome_content_utility_manifest",
     ]
   }
 }