After updating to version 0.9, the Object.prototype.toString.call( undefined ) returns [Object Window] instead of [Object Undefined] when the strict mode isn't turned on.

The root of this bug is caused by this line:

https://github.com/angular/zone.js/pull/734/files#diff-7cf54420c5bf443f7d3575ad72ac1de3R44

where this refers to the Window in non-strict mode.