Don't cache nth-indices of pseudo elements.
A pseudo element is not found in its parent's child list. That caused an
assert while trying to cache the nth-index for a ::before element while
matching style for the ::before element's scrollbar pseudo elements.
Instead, skip the caching part and traverse siblings to fall back to the
behavior we had before the NthIndexCache.
Trying to get custom scrollbar style for pseudo elements with scrolling
overflow will not work, but never did. It's not currently possible to
match ::before::-webkit-scrollbar, and a universal ::-webkit-scrollbar
will not match scrollbars in pseudo elements like ::before, either.
R=esprehn@chromium.org
BUG=481495
Review URL: https://codereview.chromium.org/1108783002
git-svn-id: svn://svn.chromium.org/blink/trunk@194728 bbb929c8-8fbe-4397-9dbb-9b2b20218538
4 files changed
