[NaCl SDK] Add keyboard interrupt handlers for python scripts

native_client_sdk/src/build_tools/build_sdk.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.
 
 """Entry point for both build and try bots.
 
 This script is invoked from XXX, usually without arguments
 to package an SDK. It automatically determines whether
 this SDK is for mac, win, linux.
@@ skipping 932 matching lines @@
   if options.archive:
     BuildStepArchiveBundle('build', pepper_ver, clnumber, tarfile)
     if platform == 'linux':
       BuildStepArchiveBundle('naclports', pepper_ver, clnumber, ports_tarfile)
     BuildStepArchiveSDKTools()
 
   return 0
 
 
 if __name__ == '__main__':
-  sys.exit(main(sys.argv))
+  try:
+    sys.exit(main(sys.argv))
+  except KeyboardInterrupt:
+    buildbot_common.ErrorExit('build_sdk: interrupted')