GN: Do not use forward_dependent_configs_from variable.

build/config/ios/rules.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.
 
 ios_app_script = "//build/config/ios/ios_app.py"
 
 template("code_sign_ios") {
   assert(defined(invoker.entitlements_path),
          "The path to the entitlements .xcent file")
   assert(defined(invoker.identity), "The code signing identity")
@@ skipping 89 matching lines @@
                              "cflags",
                              "cflags_c",
                              "cflags_cc",
                              "cflags_objc",
                              "cflags_objcc",
                              "configs",
                              "check_includes",
                              "data",
                              "data_deps",
                              "defines",
-                             "forward_dependent_configs_from",
                              "include_dirs",
                              "ldflags",
                              "public",
                              "public_configs",
                              "public_deps",
                              "sources",
                            ])
 
     if (defined(invoker.libs)) {
       libs = invoker.libs
@@ skipping 62 matching lines @@
   group(target_name) {
     deps = [
       ":$plist_gen_target_name",
       ":$bin_gen_target_name",
     ]
     if (invoker.code_signing_identity != "") {
       deps += [ ":$code_sign_gen_target_name" ]
     }
   }
 }