Source/WebCore: Add RefPtrs for parent and sibling counter nodes

Source/WebCore: Add RefPtrs for parent and sibling counter nodes
https://bugs.webkit.org/show_bug.cgi?id=75212

Reviewed by Adam Barth.

Test: fast/css/counters/reparent-table-children-with-counters-crash.html

* rendering/RenderCounter.cpp:
(WebCore::findPlaceForCounter):
(WebCore::makeCounterNode):
(WebCore::updateCounters):

LayoutTests: Test for crash when counter nodes are reparented outside of tables
https://bugs.webkit.org/show_bug.cgi?id=75212

Reviewed by Adam Barth.

* fast/css/counters/reparent-table-children-with-counters-crash-expected.txt: Added.
* fast/css/counters/reparent-table-children-with-counters-crash.html: Added.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@106852 268f45cc-cd09-0410-ab3c-d52691b4dbfc