Run browser_tests as a 25% experiment on Mac10.13 Tests & mac_chromium_rel_ng.

Bug: 828031
Change-Id: I1d4bdb235ad9d93df0653215c7c5928c471b6c16
Reviewed-on: https://chromium-review.googlesource.com/c/1277693
Reviewed-by: Robert Sesek <rsesek@chromium.org>
Commit-Queue: John Budorick <jbudorick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#599364}
2 files changed