GitLab

* Fixed webrunner_unittests (tests were not being exercised, so the
  test code drifted from the impl)
* Added webrunner_unittests, webrunner_browsertests to Fuchsia test
  bot list.


Bug: 871594
Change-Id: I3f86f2f1d76534c51236a3dea43dc898d996b121
Reviewed-on: https://chromium-review.googlesource.com/1174868
Commit-Queue: Kevin Marshall <kmarshall@chromium.org>
Reviewed-by: Wez <wez@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Cr-Commit-Position: refs/heads/master@{#584669}