bind the xul window to the hideChromeForLocation function

In order to avoid a "can't access dead object" TypeError we need to
bind the hideChromeForLocation back to the XULBrowserWindow object.
I've been struggling to write a test for this but can't come up with
anything to easily trigger and catch the error.
Merge pull request #1053 from clarkbw/addon-page-hideChromeForLocation-bind

Bug 887675 bind the xul window to the hideChromeForLocation function r=@erikvold