Hold SkTypeface in a RefPtr in FontPlatformDataChromiumWin.

This allows removal of refcounting code which is implicit when a smart
pointer is used.

BUG=254509

Review URL: https://chromiumcodereview.appspot.com/19699006

git-svn-id: svn://svn.chromium.org/blink/trunk@154652 bbb929c8-8fbe-4397-9dbb-9b2b20218538