Disable sub-pixel layout on mac.
https://bugs.webkit.org/show_bug.cgi?id=114999.

Reviewed by Simon Fraser.

* Configurations/FeatureDefines.xcconfig:
* WebCore.exp.in: 
Export symbol needed to be added for IntRect(const LayoutRect&) constructor, 
which is now being used in pixelSnappedIntRect(const LayoutRect&) in LayoutRect.h after disabling sub-pixel layout.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@149209 268f45cc-cd09-0410-ab3c-d52691b4dbfc
Unreviewed. Rebaseline a bunch of tests and run optimize-baselines after disabling sub-pixel layout on mac.
https://bugs.webkit.org/show_bug.cgi?id=114999.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@149210 268f45cc-cd09-0410-ab3c-d52691b4dbfc