[DO NOT LAND] Set @@toStringTag for DOM object prototypes

LayoutTests/svg/custom/script-tests/SVGException.js

 description("Tests the properties of the exception thrown by rotateFromVector.")
 
 var e;
 try {
     var svgDoc = document.implementation.createDocument("http://www.w3.org/2000/svg", "svg", null);
     var matrix = svgDoc.documentElement.createSVGMatrix();
     matrix.rotateFromVector(0, 0)
     // raises a InvalidAccessError
 } catch (err) {
     e = err;
 }
 
 shouldBeEqualToString("e.toString()", "InvalidAccessError: Failed to execute 'rotateFromVector' on 'SVGMatrix': Arguments cannot be zero.");
 shouldBeEqualToString("Object.prototype.toString.call(e)", "[object DOMException]");
-shouldBeEqualToString("Object.prototype.toString.call(e.__proto__)", "[object DOMExceptionPrototype]");
+shouldBeEqualToString("Object.prototype.toString.call(e.__proto__)", "[object DOMException]");
 shouldBeEqualToString("e.constructor.toString()", "function DOMException() { [native code] }");
 shouldBe("e.constructor", "window.DOMException");
 
 var successfullyParsed = true;