GitLab

Extracts parts of the regular grid layout function into a helper, which
is then used by the new grid layout function.

Test: manual
Bug: 1011973
Change-Id: I7bdf40227bbd1df467ea9d56bc84e58b01c12f33
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1867271
Commit-Queue: Sammie Quon <sammiequon@chromium.org>
Reviewed-by: Xiaoqian Dai <xdai@chromium.org>
Cr-Commit-Position: refs/heads/master@{#707460}