Convert chrome_unscaled_resources to use a qualified path.

chrome/app/theme/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("//tools/grit/grit_rule.gni")
 
 # GYP version: chrome/chrome_resources.gyp:theme_resources
 grit("theme_resources") {
   source = "theme_resources.grd"
   outputs = [
     "grit/theme_resources.h",
     "grit/theme_resources_map.cc",
     "grit/theme_resources_map.h",
     "theme_resources_100_percent.pak",
     "theme_resources_200_percent.pak",
   ]
 
   deps = [
     ":chrome_unscaled_resources",
     "//ui/resources",
   ]
 }
 
 # GYP version: chrome/chrome_resources.gyp:chrome_unscaled_resources
 grit("chrome_unscaled_resources") {
   source = "chrome_unscaled_resources.grd"
+  use_qualified_include = true
   outputs = [
     "grit/chrome_unscaled_resources.h",
     "chrome_unscaled_resources.pak",
   ]
 }