It seems that the output on snapshot failure has changed, so failed
snapshots were no longer being automatically re-run in gdb.

Change-Id: I321a6055b5683db31d215b9c30827f4badca3df7
Reviewed-on: https://chromium-review.googlesource.com/1066058Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53269}