Revert 237455 "Adding support for M32 window types, and making a..."

Speculative revert to fix chromedriver window switching tests on mac

> Adding support for M32 window types, and making app windows accessible in ChromeDriver.
> 
> R=kkania@chromium.org
> BUG=
> TEST=App windows are accessible on Chrome M32+ (beta)
> 
> Review URL: https://codereview.chromium.org/79153007

TBR=bustamante@chromium.org

Review URL: https://codereview.chromium.org/92153006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@237615 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 237615