Rebaseline svg/dom/SVGStringList-basics.xhtml

The windows expectation ended up in the xp directory instead of the general
win directory.

TBR=
BUG=

Review URL: https://codereview.chromium.org/24265003

git-svn-id: svn://svn.chromium.org/blink/trunk@158034 bbb929c8-8fbe-4397-9dbb-9b2b20218538