Why does this radial gradient with transparency work in Firefox and not Chrome?

Question

I need to create a "punchout" effect with a mask. Both the mask and punchout need an alpha transparency applied.

It works here perfectly on Firefox but not on Chrome: http://codepen.io/anon/pen/WbbXKP

What am I doing wrong?

CSS:

body {
  margin: 0;
  padding: 0;
}

.pizza {
    background: url(http://lorempizza.com/900/900/) center;
    position:absolute;
  width: 100%;
    height: 100%;
}

.overlay {
  top: 0;
  left: 0;
  opacity: .9;
  position: absolute;
  width: 100%;
  height: 100%;
  background: -moz-radial-gradient(50% 50% 45deg, circle cover, rgba(0,0,0,.8) 150px, rgba(0,0,0,1) 150px);
  background: -webkit-radial-gradient(50% 50% 45deg, circle cover, rgba(0,0,0,.8) 150px, rgba(0,0,0,1) 150px);
  background: -webkit-gradient(radial, 50% 50% 45deg, circle cover, rgba(0,0,0,.8) 150px, rgba(0,0,0,1) 150px);
}

HTML

<div class="pizza"></div>
<div class="overlay"></div>

Answer 1

Please try

background: -webkit-radial-gradient(50% 50%, circle cover,rgba(0,0,0,.8) 150px,rgba(0,0,0,1) 150px); 

The angle is not needed for the radial-gradient. Just remove 45deg