Add a use counter for author rules setting display: block on summary.
The HTML spec says to use list-item rendering to display the summary
element. This lets authors control how the disclosure triangle is
rendered with list-style-type, etc.
Today, Chromium uses display: block for the summary element. Changing
to list-item would mean authors who set display: block on summary will
not see the disclosure triangle any more.
This patch adds a use counter for pages which set display: block on
summary in author rules.
BUG=590014
Review-Url: https://codereview.chromium.org/2122613002
Cr-Commit-Position: refs/heads/master@{#403848}
4 files changed
