Remove manual --tbr support and convert it into automatic TBR= detection.

gcl.py

 #!/usr/bin/env python
 # Copyright (c) 2011 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.
 
 """\
 Wrapper script around Rietveld's upload.py that simplifies working with groups
 of files.
 """
 
@@ skipping 1216 matching lines @@
                                        change_info.patchset,
                                        None)
   output = presubmit_support.DoPresubmitChecks(
       change=change,
       committing=committing,
       verbose=False,
       output_stream=sys.stdout,
       input_stream=sys.stdin,
       default_presubmit=root_presubmit,
       may_prompt=may_prompt,
-      tbr=False,
       rietveld_obj=change_info.RpcServer())
   if not output.should_continue() and may_prompt:
     # TODO(dpranke): move into DoPresubmitChecks(), unify cmd line args.
     print "\nPresubmit errors, can't continue (use --no_presubmit to bypass)"
 
   return output
 
 
 @no_args
 def CMDchanges():
@@ skipping 213 matching lines @@
       raise
     print >> sys.stderr, (
         'AppEngine is misbehaving and returned HTTP %d, again. Keep faith '
         'and retry or visit go/isgaeup.\n%s') % (e.code, str(e))
     return 1
 
 
 if __name__ == "__main__":
   fix_encoding.fix_encoding()
   sys.exit(main(sys.argv[1:]))