Iron out some kinks in SVG IDL files

LayoutTests/svg/dom/method-argument-typechecks-expected.txt

+Check that invalid values of arguments throw TypeError.
+
+On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
+
+
+SVGAnimationElement
+
+beginElementAt(float offset)
+PASS animateElm.beginElementAt(0) did not throw exception.
+FAIL animateElm.beginElementAt(NaN) should throw an exception. Was undefined.
+FAIL animateElm.beginElementAt(Infinity) should throw an exception. Was undefined.
+
+endElementAt(float offset)
+PASS animateElm.endElementAt(0) did not throw exception.
+FAIL animateElm.endElementAt(NaN) should throw an exception. Was undefined.
+FAIL animateElm.endElementAt(Infinity) should throw an exception. Was undefined.
+
+
+SVGFEDropShadowElement
+
+setStdDeviation(float stdDeviationX, float stdDeviationY)
+PASS dropShadow.setStdDeviation(0, 0) did not throw exception.
+FAIL dropShadow.setStdDeviation(NaN, NaN) should throw an exception. Was undefined.
+FAIL dropShadow.setStdDeviation(Infinity, Infinity) should throw an exception. Was undefined.
+
+
+SVGFEGaussianBlurElement
+
+setStdDeviation(float stdDeviationX, float stdDeviationY)
+PASS gaussian.setStdDeviation(0, 0) did not throw exception.
+FAIL gaussian.setStdDeviation(NaN, NaN) should throw an exception. Was undefined.
+FAIL gaussian.setStdDeviation(Infinity, Infinity) should throw an exception. Was undefined.
+PASS successfullyParsed is true
+
+TEST COMPLETE
+