gyp_chromium: put our path in the front of sys.path

build/gyp_chromium

 #!/usr/bin/python
 
 # Copyright (c) 2009 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
 import os
 import shlex
 import sys
 
 script_dir = os.path.dirname(__file__)
 chrome_src = os.path.normpath(os.path.join(script_dir, os.pardir))
 
-sys.path.append(os.path.join(chrome_src, 'tools', 'gyp', 'pylib'))
+sys.path.insert(0, os.path.join(chrome_src, 'tools', 'gyp', 'pylib'))
 import gyp
 
 def additional_include_files(args=[]):
   """
   Returns a list of additional (.gypi) files to include, without
   duplicating ones that are already specified on the command line.
   """
   # Determine the include files specified on the command line.
   # This doesn't cover all the different option formats you can use,
   # but it's mainly intended to avoid duplicating flags on the automatic
@@ skipping 59 matching lines @@
   # to enfore syntax checking.
   syntax_check = os.environ.get('CHROMIUM_GYP_SYNTAX_CHECK')
   if syntax_check and int(syntax_check):
     args.append('--check')
 
   print 'Updating projects from gyp files...'
   sys.stdout.flush()
 
   # Off we go...
   sys.exit(gyp.main(args))