Revert 226347 "Fixes use after free caused by delete in RootWind..."

> Fixes use after free caused by delete in RootWindowController
> 
> RootWindowController::CloseChildWindows() was explicitly deleting
> windows. It should only do that for windows that are owned by the
> parent, otherwise the window should be removed.
> 
> BUG=297028
> TEST=covered by test now.
> R=oshima@chromium.org
> 
> Review URL: https://codereview.chromium.org/25374002

TBR=sky@chromium.org

Review URL: https://codereview.chromium.org/25659002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@226377 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 226377