SVGTests should not leave detached elements in the tree

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

Index: LayoutTests/svg/dynamic-updates/script-tests/SVGUseElement-dom-requiredFeatures.js
diff --git a/LayoutTests/svg/dynamic-updates/script-tests/SVGUseElement-dom-requiredFeatures.js b/LayoutTests/svg/dynamic-updates/script-tests/SVGUseElement-dom-requiredFeatures.js
index d41fc351cdad07a1f8a15ddcd6ef739a02e9cdbc..7b78eed5df0b962308af9bebf7fd69867575381e 100644
--- a/LayoutTests/svg/dynamic-updates/script-tests/SVGUseElement-dom-requiredFeatures.js
+++ b/LayoutTests/svg/dynamic-updates/script-tests/SVGUseElement-dom-requiredFeatures.js
@@ -16,20 +16,20 @@ rootSVGElement.appendChild(defsElement);
 rootSVGElement.appendChild(useElement);
 
 function repaintTest() {
-    description("Check that SVGUseElement is initially displayed");
-    shouldBeEqualToString("document.defaultView.getComputedStyle(useElement, null).display", "inline");
-    description("Check that setting requiredFeatures to something invalid makes it not render");
+    debug("Check that SVGUseElement is initially displayed");
+    shouldHaveBBox("useElement", "200", "200");
+    debug("Check that setting requiredFeatures to something invalid makes it not render");
     useElement.setAttribute("requiredFeatures", "http://www.w3.org/TR/SVG11/feature#BogusFeature");
-    shouldBeEqualToString("document.defaultView.getComputedStyle(useElement, null).display", "");
-    description("Check that setting requiredFeatures to something valid makes it render again");
+    shouldHaveBBox("useElement", "0", "0");
+    debug("Check that setting requiredFeatures to something valid makes it render again");
     useElement.setAttribute("requiredFeatures", "http://www.w3.org/TR/SVG11/feature#Shape");
-    shouldBeEqualToString("document.defaultView.getComputedStyle(useElement, null).display", "inline");
+    shouldHaveBBox("useElement", "200", "200");
     debug("Check that adding something valid to requiredFeatures keeps rendering the element");
     useElement.setAttribute("requiredFeatures", "http://www.w3.org/TR/SVG11/feature#Gradient");
-    shouldBeEqualToString("document.defaultView.getComputedStyle(useElement, null).display", "inline");
+    shouldHaveBBox("useElement", "200", "200");
     debug("Check that adding something invalid to requiredFeatures makes it not render");
     useElement.setAttribute("requiredFeatures", "http://www.w3.org/TR/SVG11/feature#BogusFeature");
-    shouldBeEqualToString("document.defaultView.getComputedStyle(useElement, null).display", "");
+    shouldHaveBBox("useElement", "0", "0");
 
     completeTest();
 }