Chromedriver builder fails on build bot steps for all desktop platforms

All they are failing on error 'Failed to convert revision to commit position' in run_buildbot_steps.py.

https://ci.chromium.org/buildbot/chromium.chromedriver/Linux/
https://ci.chromium.org/buildbot/chromium.chromedriver/Mac%2010.6/
https://ci.chromium.org/buildbot/chromium.chromedriver/Win7/

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Failed to get commit position number for abf1475f425aa7cb6c00aa3a8d953dee03c1f9f9
Traceback (most recent call last):
  File "E:\b\build\slave\chromedriver_win7\build\src\chrome\test\chromedriver\run_buildbot_steps.py", line 464, in <module>
    sys.exit(main())
  File "E:\b\build\slave\chromedriver_win7\build\src\chrome\test\chromedriver\run_buildbot_steps.py", line 416, in main
    raise Exception('Failed to convert revision to commit position')
Exception: Failed to convert revision to commit position
...