Add GYP_CHROMIUM_NO_ACTION environment variable to gyp_chromium

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 64 matching lines @@
   # Optionally add supplemental .gypi files if present.
   supplements = glob.glob(os.path.join(chrome_src, '*', 'supplement.gypi'))
   for supplement in supplements:
     AddInclude(supplement)
 
   return result
 
 if __name__ == '__main__':
   args = sys.argv[1:]
 
+  if int(os.environ.get('GYP_CHROMIUM_NO_ACTION', 0)):
+    print 'Skipping gyp_chromium due to GYP_CHROMIUM_NO_ACTION env var.'
+    sys.exit(0)
+
   # Use the Psyco JIT if available.
   if psyco:
     psyco.profile()
     print "Enabled Psyco JIT."
 
   # Fall back on hermetic python if we happen to get run under cygwin.
   # TODO(bradnelson): take this out once this issue is fixed:
   #    http://code.google.com/p/gyp/issues/detail?id=177
   if sys.platform == 'cygwin':
     python_dir = os.path.join(chrome_src, 'third_party', 'python_26')
@@ skipping 55 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))