I\'m using the clip() function on a canvas.
Results:

As you c
I came across the same issue with Chrome and clip().
In my circumstance I achieved better browser compatibility by setting the canvas globalCompositeOperation.
context.globalCompositeOperation = 'source-atop';
So draw your shape, a circle in this case. Then switch to 'source-atop' and draw your kitten image.
Note, this is a quick fix for basic drawing and assumes a blank canvas. Previous canvas drawing will affect your clip.