GitLab

Own a cc::PictureLayer directly in GraphicsLayer and LinkHighlightImpl
and expose it instead of WebContentLayer*. Wrap it in a WebLayer for
interactions that require one of those for now.

R=chrishtr@chromium.org, jbroman@chromium.org

Bug: 838693
Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
Change-Id: I5486b58337987dbfa13e2048dcdf10ae059beea5
Reviewed-on: https://chromium-review.googlesource.com/1048545
Commit-Queue: danakj <danakj@chromium.org>
Reviewed-by: Jeremy Roman <jbroman@chromium.org>
Reviewed-by: Chris Harrelson <chrishtr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#557231}