else if ('webkitLineDash' in CanvasRenderingContext2D.prototype) {
prototype = document.createElement('canvas').getContext('2d').proto;
setLineDash = function (dash) {
this.webkitLineDash = dash;
};
getLineDash = function () {
return this.webkitLineDash;
};

            setLineDashOffset = function (dashOffset) {
                this.webkitLineDashOffset = dashOffset;
            };
            getLineDashOffset = function () {
                return this.webkitLineDashOffset;
            };
        }

    Object.defineProperty(prototype, 'setLineDash', {
    			value: setLineDash,
    			enumerable: true,
    			configurable: false,
    			writeable: false
    		});

    		Object.defineProperty(prototype, 'getLineDash', {
    			value: getLineDash,
    			enumerable: true,
    			configurable: false,
    			writeable: false
    		});

    		Object.defineProperty(prototype, 'lineDashOffset', {
    			set: setLineDashOffset,
    			get: getLineDashOffset,
    			enumerable: true,
    			configurable: false,
    			writeable: false
    		});

    	}
    })();