GitLab

Make --test-launcher-filter-file support multiple filter files separated
by ';'.

Bug: 881438
Change-Id: Ibe17d1e8443cbb490a2d1b8942bb003c96a79525
Reviewed-on: https://chromium-review.googlesource.com/1213866
Commit-Queue: Chong Zhang <chongz@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#590513}