Enable building with Native Client.

sync_chromium.py

 #!/usr/bin/env python
 # Copyright 2014 The LibYuv Project Authors. All rights reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS. All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 """Script to download a Chromium checkout into the workspace.
@@ skipping 68 matching lines @@
       os.path.exists(flag_file)):
     with open(flag_file, 'r') as f:
       if f.read() == flag_file_content:
         print 'Chromium already up to date: ', opts.target_revision
         return 0
     os.unlink(flag_file)
 
   env = os.environ.copy()
 
   # Avoid downloading NaCl toolchain as part of the Chromium hooks.
-  env.setdefault('GYP_DEFINES', '')
-  env['GYP_DEFINES'] += ' disable_nacl=1'
   env['GYP_CHROMIUM_NO_ACTION'] = '1'
   gclient_cmd = 'gclient.bat' if sys.platform.startswith('win') else 'gclient'
   args = [
       gclient_cmd, 'sync', '--force', '--revision', 'src@'+opts.target_revision
   ]
 
   if os.environ.get('CHROME_HEADLESS') == '1':
     # Running on a buildbot.
     args.append('-vvv')
 
@@ skipping 46 matching lines @@
   ret = subprocess.call(args, cwd=opts.chromium_dir, env=env)
   if ret == 0:
     with open(flag_file, 'wb') as f:
       f.write(flag_file_content)
 
   return ret
 
 
 if __name__ == '__main__':
   sys.exit(main())