Use a qualified path for grit/content_resources.h.

content/content_resources.gyp

 # Copyright (c) 2012 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.
 
 # TODO(jochen): make this a .gypi file and include it in content.gyp, once
 # content.gyp doesn't depend on gyp files from chrome/ anymore:
 # http://crbug.com/10394
 {
   'targets': [
     {
       # GN version: //content:resources
       'target_name': 'content_resources',
       'type': 'none',
       'variables': {
         'grit_out_dir': '<(SHARED_INTERMEDIATE_DIR)/content',
       },
       'actions': [
         {
           'action_name': 'generate_content_resources',
           'variables': {
             'grit_grd_file': 'content_resources.grd',
           },
           'includes': [ '../build/grit_action.gypi' ],
         },
       ],
-      'includes': [ '../build/grit_target.gypi' ],
       'copies': [
         {
           'destination': '<(PRODUCT_DIR)',
           'files': [
             '<(SHARED_INTERMEDIATE_DIR)/content/content_resources.pak'
           ],
         },
       ],
     },
   ],
 }