Switch ScopedTaskEnvironment's Run() timeout to use ADD_FAILURE.

ScopedTaskEnvironment would previously LOG(FATAL) on Run() timeout,
causing the calling process to crash, preventing tests scheduled later
in the same batch from being run.

ScopedTaskEnvironment now uses MakeExpectedNotRunClosure() as the Run()
timeout callback, allowing test batches to run to completion.

Bug: 918724
Change-Id: I23269ee9d9e2c55108a57d4081f62a7769b1f44b
Reviewed-on: https://chromium-review.googlesource.com/c/1481655
Commit-Queue: Wez <wez@chromium.org>
Auto-Submit: Wez <wez@chromium.org>
Reviewed-by: Gabriel Charette <gab@chromium.org>
Cr-Commit-Position: refs/heads/master@{#634938}
2 files changed