Merge 130855 - Recursively detach SVGElementInstances

Source/WebCore/svg/SVGElementInstance.cpp

Index: Source/WebCore/svg/SVGElementInstance.cpp
===================================================================
--- Source/WebCore/svg/SVGElementInstance.cpp	(revision 130861)
+++ Source/WebCore/svg/SVGElementInstance.cpp	(working copy)
@@ -87,6 +87,9 @@
     // Clear all pointers. When the node is detached from the shadow DOM it should be removed but,
     // due to ref counting, it may not be. So clear everything to avoid dangling pointers.
 
+    for (SVGElementInstance* node = firstChild(); node; node = node->nextSibling())
+        node->detach();
+
     // Deregister as instance for passed element, if we haven't already.
     if (m_element->instancesForElement().contains(this))
         m_element->removeInstanceMapping(this);