Improve Skia configuration.

This is the Chromium side of https://codereview.chromium.org/19808007 .

R=djsollen@google.com

Review URL: https://codereview.chromium.org/19477005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@229905 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 229905