Stop setting use_qualified_include to true now that that is the default.

content/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")
 import("//build/config/nacl/config.gni")
 import("//ppapi/features/features.gni")
 
 # Applied by targets internal to content.
 config("content_implementation") {
@@ skipping 93 matching lines @@
     ]
   }
 } else {
   group("content") {
     public_deps = content_shared_components
   }
 }
 
 grit("resources") {
   source = "content_resources.grd"
-  use_qualified_include = true
   outputs = [
     "grit/content_resources.h",
     "content_resources.pak",
   ]
   grit_flags = [
     "-E",
     "root_gen_dir=" + rebase_path(root_gen_dir, root_build_dir),
   ]
   deps = [
     "//content/public/app:browser_manifest",
@@ skipping 25 matching lines @@
     sources = [
       "app/sandbox_helper_win.cc",
       "public/app/sandbox_helper_win.h",
     ]
 
     deps = [
       "//sandbox",
     ]
   }
 }