Enforce HTML range restriction on setting unsigned attribute values.

LayoutTests/fast/dom/script-tests/unsigned-long-attribute-reflection.js

 // http://whatwg.org/html#reflecting-content-attributes-in-idl-attributes
 // http://whatwg.org/html#rules-for-parsing-non-negative-integers
 function testUnsignedLong(interface, createElement, attribute)
 {
     test(function()
     {
         var element = createElement();
 
         assert_equals(element[attribute], 0);
 
@@ skipping 21 matching lines @@
         assert_false(element.hasAttribute(attribute));
 
         function t(input, output)
         {
             element[attribute] = input;
             assert_equals(element.getAttribute(attribute), output);
         }
 
         t(0, "0");
         t(2147483647, "2147483647");
-        // per spec:
-        //t(2147483648, "0");
-        //t(-1, "0");
-        // per implementation <http://crbug.com/316122>:
-        t(2147483648, "2147483648");
-        t(-1, "4294967295");
+        t(2147483648, "0");
+        t(2147483700, "0");
+        t(-1, "0");
+        t(-3, "0");
     }, "set " + interface + "." + attribute);
 }