Google Map show grey if don't have map.fitBounds

Question

Here is my live demo http://plnkr.co/edit/04jDAwoSQbIGhNUlO5n0?p=preview , try to click the button first and see if you can see the working map or just a grey area like me. Then uncomment the last line, in my test it work.
I have search for this "grey issue" but it seem each link show different isuue.
I'm using Google Chrome 33 on Linux 64 bit.

Answer 1

you've ommitted the required map-options zoom and center