[NaCl SDK] Make mono buildbot script run in the proper directory.

native_client_sdk/src/build_tools/nacl-mono-buildbot.py

 #!/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.
 
 import hashlib
 import json
 import os
 import sys
 
@@ skipping 142 matching lines @@
   buildbot_common.Run([buildbot_common.GetGsutil(), 'cp', '-a', 'public-read',
       MONO_MANIFEST, GS_MANIFEST_PATH + MONO_MANIFEST])
   
 
 def main(args):
   args = args[1:]
 
   buildbot_revision = os.environ.get('BUILDBOT_REVISION', '')
   buildername = os.environ.get('BUILDBOT_BUILDERNAME', '')
 
+  os.chdir(buildbot_common.SCRIPT_DIR)
+
   if buildername == 'linux-sdk-mono32':
     assert buildbot_revision
     sdk_revision = buildbot_revision.split(':')[0]
     pepper_revision = build_utils.ChromeMajorVersion()
     build_and_upload_mono(sdk_revision, pepper_revision, None,
                           'trunk.' + sdk_revision, args)
   elif buildername == 'linux-sdk-mono64':
     infos = get_sdk_build_info()
     for info in infos:
       # This will put the file in naclmono_19/1/naclmono_19.bz2 for example.
       upload_path = info['naclmono_name'] + '/' + info['naclmono_rev']
       build_and_upload_mono(None, info['pepper_revision'], info['sdk_url'],
           upload_path, args)
     update_mono_sdk_json(infos)
     
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv))