Enable content_shell_crash_test on many bots.

On most bots, we don't know why the test is disabled. Worst case, we'll find
out and redisable it on bots where it doesn't yet work for some reason.

On Mac 10.13 and Win 7, we do know why it's disabled, but the Win 7 bug
has been fixed, and the 10.13 bug was spurious and I have put in better
debug logging if it were to fail again, and I haven't seen any failures in
the last 200 builds on the main waterfall.

Bug: 846729,813163,843511
Change-Id: Ibd14dea1c5fb72bc4d298b53f55e87be05aa211e
Reviewed-on: https://chromium-review.googlesource.com/1120225
Commit-Queue: Nico Weber <thakis@chromium.org>
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#571572}
6 files changed