Add resource whitelisting to android_webview pak files.

android_webview/webview_repack_locales.gni

 # 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.
 
 import("//tools/grit/repack.gni")
 import("webview_repack_locales_list.gni")
 
 # Wraps repack_locales(), setting the source_patterns and deps required for
 # Chrome.
 template("webview_repack_locales") {
   repack_locales(target_name) {
     forward_variables_from(invoker, "*")
+    if (!defined(deps)) {
+      deps = []
+    }
 
     # Adding webview specific pak file? You should add it to
     # webview_repack_locales_source_patterns, so it is also included in
     # Monochrome.
 
     source_patterns = [
       "${root_gen_dir}/android_webview/components_strings_",
       "${root_gen_dir}/content/app/strings/content_strings_",
       "${root_gen_dir}/ui/strings/app_locale_settings_",
     ]
-    deps = [
+    deps += [
       "//android_webview:generate_components_strings",
       "//content/app/strings",
       "//ui/strings:app_locale_settings",
     ]
     source_patterns += webview_repack_locales_source_patterns
     deps += webview_repack_locales_deps
     output_dir = "$root_out_dir/android_webview/locales"
   }
 }