Without this we get an ugly stack trace. This is way more
friendly.

Bug: 983006

Change-Id: I5ba871ad71ad43bb48d91697e96473afbfe399a0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1697221
Auto-Submit: Eli Ribble <eliribble@chromium.org>
Commit-Queue: Robbie Iannucci <iannucci@chromium.org>
Reviewed-by: Robbie Iannucci <iannucci@chromium.org>