SVGTests should not leave detached elements in the tree

LayoutTests/svg/dynamic-updates/script-tests/SVGGElement-dom-requiredFeatures.js

Index: LayoutTests/svg/dynamic-updates/script-tests/SVGGElement-dom-requiredFeatures.js
diff --git a/LayoutTests/svg/dynamic-updates/script-tests/SVGGElement-dom-requiredFeatures.js b/LayoutTests/svg/dynamic-updates/script-tests/SVGGElement-dom-requiredFeatures.js
index 2b5de873339d57feed5dbcd67eceee671f30fbe0..87a8cd8448e768e5aa140e1139caa08421b7e116 100644
--- a/LayoutTests/svg/dynamic-updates/script-tests/SVGGElement-dom-requiredFeatures.js
+++ b/LayoutTests/svg/dynamic-updates/script-tests/SVGGElement-dom-requiredFeatures.js
@@ -4,24 +4,28 @@
 createSVGTestCase();
 
 var gElement = createSVGElement("g");
+var imageElement = createSVGElement("image");
+imageElement.setAttribute("width", "200");
+imageElement.setAttribute("height", "200");
 
+gElement.appendChild(imageElement);
 rootSVGElement.appendChild(gElement);
 
 function repaintTest() {
     debug("Check that SVGGElement is initially displayed");
-    shouldBeEqualToString("document.defaultView.getComputedStyle(gElement, null).display", "inline");
+    shouldHaveBBox("gElement.firstElementChild", "200", "200");
     debug("Check that setting requiredFeatures to something invalid makes it not render");
     gElement.setAttribute("requiredFeatures", "http://www.w3.org/TR/SVG11/feature#BogusFeature");
-    shouldBeEqualToString("document.defaultView.getComputedStyle(gElement, null).display", "");
+    shouldHaveBBox("gElement.firstElementChild", "0", "0");
     debug("Check that setting requiredFeatures to something valid makes it render again");
     gElement.setAttribute("requiredFeatures", "http://www.w3.org/TR/SVG11/feature#Shape");
-    shouldBeEqualToString("document.defaultView.getComputedStyle(gElement, null).display", "inline");
+    shouldHaveBBox("gElement.firstElementChild", "200", "200");
     debug("Check that adding something valid to requiredFeatures keeps rendering the element");
     gElement.setAttribute("requiredFeatures", "http://www.w3.org/TR/SVG11/feature#Gradient");
-    shouldBeEqualToString("document.defaultView.getComputedStyle(gElement, null).display", "inline");
+    shouldHaveBBox("gElement.firstElementChild", "200", "200");
     debug("Check that adding something invalid to requiredFeatures makes it not render");
     gElement.setAttribute("requiredFeatures", "http://www.w3.org/TR/SVG11/feature#BogusFeature");
-    shouldBeEqualToString("document.defaultView.getComputedStyle(gElement, null).display", "");
+    shouldHaveBBox("gElement.firstElementChild", "0", "0");
 
     completeTest();
 }