Roll Skia DEPS to r12159

R=rmistry@google.com

Review URL: https://codereview.chromium.org/60183005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@233606 0039d316-1c4b-4281-b951-d872f2087c98
Update .DEPS.git

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@233607 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 233606
SVN changes up to revision 233607