Check for both CanvasGradient and CanvasPattern in ctx.strokeStyle and ctx.fillStyle.

lib/context2d.js

@@ -165,7 +165,7 @@ Context2d.prototype.setTransform = function(){
  */
 
 Context2d.prototype.__defineSetter__('fillStyle', function(val){
-  if ('CanvasGradient' == val.constructor.name) {
+  if (~['CanvasGradient','CanvasPattern'].indexOf(val.constructor.name)) {
     this.lastFillStyle = val;
     this._setFillPattern(val);
   } else if ('string' == typeof val) {
@@ -191,7 +191,7 @@ Context2d.prototype.__defineGetter__('fillStyle', function(){
  */
 
 Context2d.prototype.__defineSetter__('strokeStyle', function(val){
-  if ('CanvasGradient' == val.constructor.name) {
+  if (~['CanvasGradient','CanvasPattern'].indexOf(val.constructor.name)) {
     this.lastStrokeStyle = val;
     this._setStrokePattern(val);
   } else if ('string' == typeof val) {