Clang: Roll skia to 583.

See http://code.google.com/p/skia/source/detail?r=583

TBR=evanm

Review URL: http://codereview.chromium.org/2823032

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@50946 0039d316-1c4b-4281-b951-d872f2087c98