GitLab

* Make it a little easier to understand
* Remove some panel-related code (a lot more of that in a separate CL)

No change in behavior.

Bug: 805612
Bug: 788033
Change-Id: I70225cc90cba940a8e2cb148be4aa887ebaa01ce
Reviewed-on: https://chromium-review.googlesource.com/1150776
Commit-Queue: Manu Cornet <manucornet@chromium.org>
Reviewed-by: Michael Wasserman <msw@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#579869}