Revert 225755 "Makes destruction of DesktopNativeWidgetAura saner"

> Makes destruction of DesktopNativeWidgetAura saner
> 
> Prior to this patch DesktopNativeWidgetAura destruction keyed off
> destruction of the window_ (not the rootwindow). This meant that by
> the time we destroyed the Widget the RootWindow was still live. This
> meant any children of the rootwindow, such as child widgets, were
> alive as well. The general expectation is that by the time a Widget is
> destroyed and child Widgets have also been destroyed.
> 
> This patch changes destruction so that we key off the
> AcceleratedWidget going away. When that happens we destroy the
> RootWindow. By doing this we ensure child Widgets have also been
> destroyed.
> 
> BUG=288953
> TEST=covered by test
> R=ben@chromium.org
> 
> Review URL: https://codereview.chromium.org/24515004

TBR=sky@chromium.org

Review URL: https://codereview.chromium.org/25045005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@225767 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 225767