The extend mode of canvas gradients isn't under user control as it is in SVG. I'd like to propose adding a setExtend(in DOMString extend) method to the CanvasGradient interface[1], where the method would accept the arguments "none", "repeat", "reflect" and "pad". These would be defined similarly to the values that the 'spreadMethod' attribute on SVG gradients accepts[2].
Jonathan [1] http://www.whatwg.org/specs/web-apps/current-work/multipage/the-canvas-element.html#canvasgradient [2] http://www.w3.org/TR/SVG11/pservers.html#LinearGradientElementSpreadMethodAttribute
