Unreviewed, rolling out r143844.
http://trac.webkit.org/changeset/143844
https://bugs.webkit.org/show_bug.cgi?id=110241

It broke Chromium Mac Release Build

* WebCore.gyp/WebCore.gyp:
* WebCore.gyp/WebCoreGTK.gyp: Removed.
* WebCore.gypi:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@143854 268f45cc-cd09-0410-ab3c-d52691b4dbfc