Update Element API for CSSOM smooth scrolling to match the spec

LayoutTests/fast/dom/script-tests/non-numeric-values-numeric-parameters.js

 description(
 'This tests the behavior of non-numeric values in contexts where the DOM has a numeric parameter.'
 );
 
 function nonNumericPolicy(template)
 {
     var x = 0;
     try {
         eval(template);
     } catch (e) {
@@ skipping 191 matching lines @@
 shouldBe("nonNumericPolicy('createCSSStyleSheet().addRule(selector, styleText, x)')", "'any type allowed'");
 shouldBe("nonNumericPolicy('createCSSStyleSheet().removeRule(x)')", "'any type allowed'");
 
 // Document
 
 shouldBe("nonNumericPolicy('document.elementFromPoint(x, 0)')", "'any type allowed'");
 shouldBe("nonNumericPolicy('document.elementFromPoint(0, x)')", "'any type allowed'");
 
 // Element
 
-shouldBe("nonNumericPolicy('document.body.scrollLeft = x')", "'mixed'");
-shouldBe("nonNumericPolicy('document.body.scrollTop = x')", "'mixed'");
+shouldBe("nonNumericPolicy('document.body.scrollLeft = x')", "'any type allowed'");
+shouldBe("nonNumericPolicy('document.body.scrollTop = x')", "'any type allowed'");
 
 // History
 
 // Not tested: go.
 
 // HTMLCollection
 
 shouldBe("nonNumericPolicy('document.images.item(x)')", "'any type allowed'");
 
 // HTMLInputElement
@@ skipping 399 matching lines @@
 ../../../../WebCore/svg/SVGSVGElement.idl:                 attribute float currentScale
 
 ../../../../WebCore/svg/SVGMatrix.idl:        attribute double a;
 ../../../../WebCore/svg/SVGMatrix.idl:        attribute double b;
 ../../../../WebCore/svg/SVGMatrix.idl:        attribute double c;
 ../../../../WebCore/svg/SVGMatrix.idl:        attribute double d;
 ../../../../WebCore/svg/SVGMatrix.idl:        attribute double e;
 ../../../../WebCore/svg/SVGMatrix.idl:        attribute double f;
 
 */