Don't require getPropertyCSSValue in svg number animation tests

LayoutTests/svg/animations/script-tests/svgnumber-animation-3.js

 description("Test for SVGNumber animation with invalid units.");
 createSVGTestCase();
 
 // Setup test document
 var rect = createSVGElement("rect");
 rect.setAttribute("id", "rect");
 rect.setAttribute("x", "0");
 rect.setAttribute("width", "100");
 rect.setAttribute("height", "100");
 rect.setAttribute("fill", "green");
 rect.setAttribute("opacity", "0");
 rect.setAttribute("onclick", "executeTest()");
 
 var animate = createSVGElement("animate");
 animate.setAttribute("id", "animation");
 animate.setAttribute("attributeName", "opacity");
 animate.setAttribute("begin", "click");
 animate.setAttribute("dur", "4s");
 animate.setAttribute("from", "0px");
 animate.setAttribute("to", "1px");
 rect.appendChild(animate);
 rootSVGElement.appendChild(rect);
 
 // Setup animation test
-function sample1() {
+function sample() {
     // Check initial/end conditions
-    shouldBe("getComputedStyle(rect).getPropertyCSSValue('opacity').getFloatValue(CSSPrimitiveValue.CSS_NUMBER)", "0");
-}
-
-function sample2() {
-    shouldBe("getComputedStyle(rect).getPropertyCSSValue('opacity').getFloatValue(CSSPrimitiveValue.CSS_NUMBER)", "0");
-}
-
-function sample3() {
-    shouldBe("getComputedStyle(rect).getPropertyCSSValue('opacity').getFloatValue(CSSPrimitiveValue.CSS_NUMBER)", "0");
+    shouldBe("getComputedStyle(rect).opacity", "'0'");
 }
 
 function executeTest() {
     const expectedValues = [
         // [animationId, time, sampleCallback]
-        ["animation", 0.0,   sample1],
-        ["animation", 2.0,   sample2],
-        ["animation", 3.999, sample3],
-        ["animation", 4.001, sample1]
+        ["animation", 0.0,   sample],
+        ["animation", 2.0,   sample],
+        ["animation", 3.999, sample],
+        ["animation", 4.001, sample]
     ];
 
     runAnimationTest(expectedValues);
 }
 
 var successfullyParsed = true;