commit 14420cfe85731189c947c266de7fe803c4014450
author Vladimir Levin <vmpstr@chromium.org> Mon Feb 11 21:15:59 2019
committer Commit Bot <commit-bot@chromium.org> Mon Feb 11 21:15:59 2019
tree 0caed66bf912cf8e1c1d921ac6820c3a7cd939f7
parent 9f53096d939d84c4cf8319265114e8e1e505d407

[DL]: Keep a reference to the Document on the DL context.

This patch adds a weak member to the document associated with the locked
element. This accomplishes two things:
1. It simplifies access to the document instead of going through element_.
2. It ensures that if the element_ is destroyed we can still keep the
   locked context counts updated on the document. If the document goes
   away, then we're safe anyway since the counts are destroyed along with
   it.

R=chrishtr@chromium.org

Bug: 882663
Change-Id: Iabbbc185c1b9199aba1f22dccd6837fe6f98a4df
Reviewed-on: https://chromium-review.googlesource.com/c/1456641
Reviewed-by: Chris Harrelson <chrishtr@chromium.org>
Commit-Queue: vmpstr <vmpstr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#630931}