Since no one can upload or land changes from Rietveld anymore,
PRESUBMIT and its support files no longer need to be able to
support it.

R=tandrii@chromium.org

Bug: 770408
Change-Id: I749092b66fdca16d5cef77e8cefc905aa5375b50
Reviewed-on: https://chromium-review.googlesource.com/693380
Commit-Queue: Aaron Gable <agable@chromium.org>
Reviewed-by: Andrii Shyshkalov <tandrii@chromium.org>