[New Multicolumn] Add a positioned object pagination test.
https://bugs.webkit.org/show_bug.cgi?id=110480.

Reviewed by Antti Koivisto.

* fast/multicol/newmulticol/positioned-split-expected.html: Added.
* fast/multicol/newmulticol/positioned-split.html: Added.



git-svn-id: svn://svn.chromium.org/blink/trunk@143609 bbb929c8-8fbe-4397-9dbb-9b2b20218538