clang upload script: Skip prompt for commit message

tools/clang/scripts/upload_revision.py

 #!/usr/bin/env python
 # Copyright (c) 2016 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 takes a Clang revision as an argument, it then
 creates a feature branch, puts this revision into update.py, uploads
 a CL, triggers Clang Upload try bots, and tells what to do next"""
 
 import argparse
@@ skipping 54 matching lines @@
   clang_old_revision = PatchRevision(clang_revision, clang_sub_revision)
 
   Git(["checkout", "-b", "clang-{}-{}".format(
       clang_revision, clang_sub_revision)])
   Git(["add", UPDATE_PY_PATH])
 
   commit_message = 'Ran `{}`.'.format(' '.join(sys.argv))
   Git(["commit", "-m", "Roll clang {}:{}.\n\n{}".format(
       clang_old_revision, clang_revision, commit_message)])
 
-  Git(["cl", "upload"])
+  Git(["cl", "upload", "-f"])
   Git(["cl", "try", "-b", "linux_upload_clang", "-r", git_revision])
   Git(["cl", "try", "-b", "mac_upload_clang", "-r", git_revision])
   Git(["cl", "try", "-b", "win_upload_clang", "-r", git_revision])
 
   print ("Please, wait until the try bots succeeded "
          "and then push the binaries to goma.")
 
 if __name__ == '__main__':
   sys.exit(main())