Fix imports in gcc_toolchain.gni to not rely on //tools.

tools/grit/grit_rule.gni

 # 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.
 
 # Instantiate grit. This will produce a script target to run grit, and a
 # static library that compiles the .cc files.
 #
 # Parameters
 #
 #   source (required)
@@ skipping 66 matching lines @@
 #     grit_flags = [ "-E", "foo=bar" ]  # Optional extra flags.
 #     # You can also put deps here if the grit source depends on generated
 #     # files.
 #   }
 import("//build/config/chrome_build.gni")
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//third_party/closure_compiler/closure_args.gni")
 
-declare_args() {
-  # Enables used resource whitelist generation. Set for official builds only
-  # as a large amount of build output is generated.
-  enable_resource_whitelist_generation = is_android && is_official_build
-}
-
 assert(!enable_resource_whitelist_generation || is_android,
        "resource whitelist generation only works on android")
 
 grit_defines = []
 
 # Mac and iOS want Title Case strings.
 use_titlecase_in_grd_files = is_mac || is_ios
 if (use_titlecase_in_grd_files) {
   grit_defines += [
     "-D",
@@ skipping 408 matching lines @@
     if (defined(invoker.configs)) {
       configs += invoker.configs
     }
 
     if (defined(invoker.visibility)) {
       visibility = invoker.visibility
     }
     output_name = grit_output_name
   }
 }