GitLab

It looks like some of the bots are still having problems with the
preloading browser test. This ensures we use full paths for referencing
files.

BUG=794629

Change-Id: I814d74bf973968350207e4b6f4879f767c82a225
Reviewed-on: https://chromium-review.googlesource.com/827135Reviewed-by: Mounir Lamouri <mlamouri@chromium.org>
Commit-Queue: Becca Hughes <beccahughes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#524131}