Fix create_include_gyp.py to support relative paths to include_js.gypi

third_party/closure_compiler/externs/compiled_resources2.gyp

 # Copyright 2017 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.
 
 ########################################################
 #    NOTE: THIS FILE IS GENERATED. DO NOT EDIT IT!     #
 # Instead, run create_include_gyp.py to regenerate it. #
 ########################################################
 {
   'targets': [
@@ skipping 91 matching lines @@
     },
     {
       'target_name': 'users_private',
       'includes': ['../include_js.gypi'],
     },
     {
       'target_name': 'web_animations',
       'includes': ['../include_js.gypi'],
     },
   ],
-}
+}