$window mocking not working without document since 1.3.0

I have tests for a directive that uses `$window`. Since 1.3.0 I cannot mock `$window` without having `document` property in `$window`.

I have a JSFiddle demonstrating this problem:
- [Both tests are passing in 1.3.0-rc.5](http://jsfiddle.net/tjokimie/65j7jk1u/1/)
- [Test without `document` is failing in 1.3.0](http://jsfiddle.net/tjokimie/2w61uamk/1/)
