Added use counter for display:contents.

Bug: 657748
Change-Id: Ib2d298388c4a68a5992a5ef14e4fad28dee04c57
Reviewed-on: https://chromium-review.googlesource.com/823924
Commit-Queue: Philip Jägenstedt <foolip@chromium.org>
Reviewed-by: Philip Jägenstedt <foolip@chromium.org>
Cr-Commit-Position: refs/heads/master@{#523755}
3 files changed