Add an command line flag for internal testing

Bug: 944726
Change-Id: I95f2f83bda789cfd1c15c125c8ee013d9f9d1aa9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1542741
Reviewed-by: Ted Choc <tedchoc@chromium.org>
Commit-Queue: Shuo Weng <shuow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#645689}
2 files changed