GitLab

This is to
* Clarify what code exists in the app shim side, and what code
  exists on the browser side.
* Ensure (via include rules) that the app shim side not call back into
  any ui/views code (that is, that it always goes through appropriate
  interfaces).

R=ellyjones
TBR=bsalomon (skia/OWNERship)

Bug: 821561
Change-Id: I4b3d48dac707507bc1881f9a1a0478ac1d15355c
Reviewed-on: https://chromium-review.googlesource.com/1247526
Commit-Queue: ccameron <ccameron@chromium.org>
Reviewed-by: Elly Fong-Jones <ellyjones@chromium.org>
Cr-Commit-Position: refs/heads/master@{#595130}