Remove SVGElementInstance

Source/core/svg/SVGElement.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2008 Rob Buis <buis@kde.org>
  * Copyright (C) 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Alp Toker <alp@atoker.com>
  * Copyright (C) 2009 Cameron McCormack <cam@mcc.id.au>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 89 matching lines @@
         m_SVGRareData.clear();
     }
 
     // With Oilpan, either removedFrom has been called or the document is dead
     // as well and there is no reason to clear out the extensions.
     document().accessSVGExtensions().rebuildAllElementReferencesForTarget(this);
     document().accessSVGExtensions().removeAllElementReferencesForTarget(this);
 #endif
 }
 
+void SVGElement::detach(const AttachContext& context)
+{
+    Element::detach(context);
+    if (correspondingElement())

[esprehn, 2014/06/05 20:57:24]

Save in a local in the if()

+        correspondingElement()->removeInstanceMapping(this);
+}
+
+void SVGElement::attach(const AttachContext& context)
+{
+    Element::attach(context);
+    if (correspondingElement())

[esprehn, 2014/06/05 20:57:24]

There's a hidden branch in there, I'd suggest:

if (SVGElement* element = correspondingElement())
  element->mapInstanceToElement(this);

+        correspondingElement()->mapInstanceToElement(this);
+}
+
 short SVGElement::tabIndex() const
 {
     if (supportsFocus())
         return Element::tabIndex();
     return -1;
 }
 
 void SVGElement::willRecalcStyle(StyleRecalcChange change)
 {
     if (!hasSVGRareData())
@@ skipping 203 matching lines @@
         document().accessSVGExtensions().removeAllElementReferencesForTarget(this);
     }
 
     invalidateInstances();
 }
 
 void SVGElement::childrenChanged(bool changedByParser, Node* beforeChange, Node* afterChange, int childCountDelta)
 {
     Element::childrenChanged(changedByParser, beforeChange, afterChange, childCountDelta);
 
-    // Invalidate all SVGElementInstances associated with us.
+    // Invalidate all instances associated with us.
     if (!changedByParser)
         invalidateInstances();
 }
 
 CSSPropertyID SVGElement::cssPropertyIdForSVGAttributeName(const QualifiedName& attrName)
 {
     if (!attrName.namespaceURI().isNull())
         return CSSPropertyInvalid;
 
     static HashMap<StringImpl*, CSSPropertyID>* propertyNameToIdMap = 0;
@@ skipping 174 matching lines @@
     ASSERT(!instances.contains(instance));
 
     instances.add(instance);
 }
 
 void SVGElement::removeInstanceMapping(SVGElement* instance)
 {
     ASSERT(instance);
     ASSERT(instance->inUseShadowTree());
 
+    if (!hasSVGRareData())
+        return;
+
     WillBeHeapHashSet<RawPtrWillBeWeakMember<SVGElement> >& instances = svgRareData()->elementInstances();
     ASSERT(instances.contains(instance));
 
     instances.remove(instance);
 }
 
 static WillBeHeapHashSet<RawPtrWillBeWeakMember<SVGElement> >& emptyInstances()
 {
 #if ENABLE(OILPAN)
     DEFINE_STATIC_LOCAL(Persistent<HeapHashSet<WeakMember<SVGElement> > >, emptyInstances, (new HeapHashSet<WeakMember<SVGElement> >));
@@ skipping 497 matching lines @@
     const WillBeHeapHashSet<RawPtrWillBeWeakMember<SVGElement> >::const_iterator end = set.end();
     for (WillBeHeapHashSet<RawPtrWillBeWeakMember<SVGElement> >::const_iterator it = set.begin(); it != end; ++it) {
         (*it)->setCorrespondingElement(0);
 
         if (SVGUseElement* element = (*it)->correspondingUseElement()) {
             ASSERT(element->inDocument());
             element->invalidateShadowTree();
         }
     }
 
+    svgRareData()->elementInstances().clear();
+
     document().updateRenderTreeIfNeeded();
 }
 
 SVGElement::InstanceUpdateBlocker::InstanceUpdateBlocker(SVGElement* targetElement)
     : m_targetElement(targetElement)
 {
     if (m_targetElement)
         m_targetElement->setInstanceUpdatesBlocked(true);
 }
 
@@ skipping 111 matching lines @@
 #endif
 
 void SVGElement::trace(Visitor* visitor)
 {
     visitor->trace(m_elementsWithRelativeLengths);
     visitor->trace(m_SVGRareData);
     Element::trace(visitor);
 }
 
 }