Trying to run |git cl upload| after commtting a spurious change to net/android/java/src/org/chromium/new/ProxyChangeListener.java causes a crash with the following stacktrace:

Running presubmit upload checks ...
Error: Could not find or load main class com.puppycrawl.tools.checkstyle.Main
Traceback (most recent call last):
  File "/Users/lilyhoughton/depot_tools/git_cl.py", line 6209, in <module>
    sys.exit(main(sys.argv[1:]))
  File "/Users/lilyhoughton/depot_tools/git_cl.py", line 6191, in main
    return dispatcher.execute(OptionParser(), argv)
  File "/Users/lilyhoughton/depot_tools/subcommand.py", line 252, in execute
    return command(parser, args[1:])
  File "/Users/lilyhoughton/depot_tools/git_cl.py", line 5043, in CMDupload
    return cl.CMDUpload(options, args, orig_args)
  File "/Users/lilyhoughton/depot_tools/git_cl.py", line 1646, in CMDUpload
    change=change)
  File "/Users/lilyhoughton/depot_tools/git_cl.py", line 1578, in RunHook
    gerrit_obj=self._codereview_impl.GetGerritObjForPresubmit())
  File "/Users/lilyhoughton/depot_tools/presubmit_support.py", line 1421, in DoPresubmitChecks
    results += executer.ExecPresubmitScript(presubmit_script, filename)
  File "/Users/lilyhoughton/depot_tools/presubmit_support.py", line 1328, in ExecPresubmitScript
    result = eval(function_name + '(*__args)', context)
  File "<string>", line 1, in <module>
  File "<string>", line 2791, in CheckChangeOnUpload
  File "<string>", line 2524, in _CommonChecks
  File "<string>", line 1530, in _CheckJavaStyle
  File "/Users/lilyhoughton/chromium/src/tools/android/checkstyle/checkstyle.py", line 60, in RunCheckstyle
    formatted_checkstyle_output = FormatCheckstyleOutput(stdout)
  File "/Users/lilyhoughton/chromium/src/tools/android/checkstyle/checkstyle.py", line 21, in FormatCheckstyleOutput
    if 'Checkstyle ends with' in lines[-1]:
IndexError: list index out of range

The change in question is simply adding or changing a comment in the file.  (In this case, s/proxy/proxy_resolution/ on line 253, though I was able to reproduce with other, equally insignificant-seeming changes).