Update from https://crrev.com/303153

build/gyp_chromium

 #!/usr/bin/env python
 
 # 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.
 
 # This script is wrapper for Chromium that adds some support for how GYP
 # is invoked by Chromium beyond what can be done in the gclient hooks.
 
 import glob
@@ skipping 160 matching lines @@
   specified_includes = set()
   for arg in args:
     if arg.startswith('-I') and len(arg) > 2:
       specified_includes.add(os.path.realpath(arg[2:]))
 
   result = []
   def AddInclude(path):
     if os.path.realpath(path) not in specified_includes:
       result.append(path)
 
+  if os.environ.get('GYP_INCLUDE_FIRST') != None:
+    AddInclude(os.path.join(chrome_src, os.environ.get('GYP_INCLUDE_FIRST')))
+
   # Always include common.gypi.
   AddInclude(os.path.join(script_dir, 'common.gypi'))
 
   # Optionally add supplemental .gypi files if present.
   for supplement in supplemental_files:
     AddInclude(supplement)
 
+  if os.environ.get('GYP_INCLUDE_LAST') != None:
+    AddInclude(os.path.join(chrome_src, os.environ.get('GYP_INCLUDE_LAST')))
+
   return result
 
 
 if __name__ == '__main__':
   # Disabling garbage collection saves about 1 second out of 16 on a Linux
   # z620 workstation. Since this is a short-lived process it's not a problem to
   # leak a few cyclyc references in order to spare the CPU cycles for
   # scanning the heap.
   import gc
   gc.disable()
@@ skipping 115 matching lines @@
 
   if not use_analyzer:
     vs2013_runtime_dll_dirs = vs_toolchain.SetEnvironmentAndGetRuntimeDllDirs()
     if vs2013_runtime_dll_dirs:
       x64_runtime, x86_runtime = vs2013_runtime_dll_dirs
       vs_toolchain.CopyVsRuntimeDlls(
         os.path.join(chrome_src, GetOutputDirectory()),
         (x86_runtime, x64_runtime))
 
   sys.exit(gyp_rc)