GitLab

Makes the constructor not call a virtual method by adding a non-
virtual helper function, avoiding the need for a wordy comment.
This also avoids extra work, since UpdateCrashKeys() only needs
to be called once during object construction, rather than once
per already-active trial.

Also fixes the unit test on iOS device by adding extra initialization
& clean up.

Bug: 309729, 821162
Change-Id: Icc6c8730bbada99167945b3353bb0d60b7f58600
Reviewed-on: https://chromium-review.googlesource.com/961488Reviewed-by: Ilya Sherman <isherman@chromium.org>
Commit-Queue: Alexei Svitkine <asvitkine@chromium.org>
Cr-Commit-Position: refs/heads/master@{#542960}