test(*): fix tests for Safari 10+

The mocksSpec change is due to the following issue in Safari 10+ strict mode:
In the following code, Safari will not use the name of the enclosing function (testCaller)
in the stack, but rather list the anonymous function that is called to inject:

```
function testCaller() {
  return inject(function() {
    throw new Error();
  });
}
var throwErrorFromInjectCallback = testCaller();
```

Naming the anonymous function allows us to check for it in the test.