Revert 235626 "Remove blacklisting of Mac OS 10.6 and 10.7."

Speculative; will follow up with more details

> Remove blacklisting of Mac OS 10.6 and 10.7.
> 
> Add blacklisting of VMWare driver on 10.7 because it hangs.
> 
> Disable compositing expectation test on 10.7 because it will
> give different results depending on whether it is running on
> a VM or real hardware.
> 
> TBR=vangelis
> BUG=266186
> 
> Review URL: https://codereview.chromium.org/68253005

TBR=ccameron@chromium.org

Review URL: https://codereview.chromium.org/75013002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@235644 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 235644