[Ozone] Unit tests for SoftwareSurfaceFactoryOzone

BUG=

Review URL: https://codereview.chromium.org/27217009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@229629 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 229629