GitLab

This provides a consistent alignment point for theme authors, makes some themes
(e.g. Dots) look correct (other themes want other values, e.g. 0, so there's no
one "right way" here), and prevents mirroring above the top of the frame image
in Refresh, since no mode has a frame height above the tabs > 16 DIP.

Bug: 866671
Change-Id: I1d79627e2735d54a332013ee70a2c71f107a898f
Reviewed-on: https://chromium-review.googlesource.com/1157878
Commit-Queue: Peter Kasting <pkasting@chromium.org>
Reviewed-by: Evan Stade <estade@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: Bret Sepulveda <bsep@chromium.org>
Cr-Commit-Position: refs/heads/master@{#580615}