login: Add special flags to Chrome startup for CfMs.

If the device is a CfM, add the
--enable-blink-features=MediaStreamTrackContentHint flag to Chrome startup.

BUG=chromium:707892
TEST=Chrome on CfM starts with the flag added.

Change-Id: Ia1d411f53bb140d20b3546551a21afe2bcf88ed1
Reviewed-on: https://chromium-review.googlesource.com/486081
Commit-Ready: Rahul Chaturvedi <rkc@chromium.org>
Tested-by: Rahul Chaturvedi <rkc@chromium.org>
Reviewed-by: Dan Erat <derat@chromium.org>
(cherry picked from commit c68bb30b1428690f94a545ce33b9a3e3d8b0c151)
Reviewed-on: https://chromium-review.googlesource.com/491947
Commit-Queue: Rahul Chaturvedi <rkc@chromium.org>
2 files changed