How can I vsync callback on HTML5 canvas?
There's no such thing. The browser should take care of doing the appropriate syncs, and you can help it by using requestAnimationFrame()
- see, for example, http://paulirish.com/2011/requestanimationframe-for-smart-animating/ and https://developer.mozilla.org/en-US/docs/Web/API/window/requestAnimationFrame.