Test Runner: Disable watchdog when debugger attached. Bug: angleproject:3162 Change-Id: I3685a4fe068b6e82b8bb04448c212788f563ab8b Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2483463 Commit-Queue: Jamie Madill <jmadill@chromium.org> Reviewed-by: Yuly Novikov <ynovikov@chromium.org>