update size only if truthy

Author: sorvell

core-icon.html

@@ -102,7 +102,9 @@
     },
 
     updateIcon: function() {
-      this.style.width = this.style.height = this.size ? this.size + 'px' : '';
+      if (this.size) {
+        this.style.width = this.style.height = this.size + 'px';
+      }
       if (this.icon) {
         var parts = String(this.icon).split(':');
         var icon = parts.pop();