Improve handling of duplicate id's for SVG resources

third_party/WebKit/Source/core/layout/svg/LayoutSVGResourceContainer.h

 /*
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
  *
  * 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
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 45 matching lines @@
   virtual LayoutSVGResourceType resourceType() const = 0;
 
   bool isSVGPaintServer() const {
     LayoutSVGResourceType resourceType = this->resourceType();
     return resourceType == PatternResourceType ||
            resourceType == LinearGradientResourceType ||
            resourceType == RadialGradientResourceType;
   }
 
   void idChanged(const AtomicString& oldId, const AtomicString& newId);
+  void detachAllClients(const AtomicString& toId);
 
   void invalidateCacheAndMarkForLayout(SubtreeLayoutScope* = nullptr);
 
   static void markForLayoutAndParentResourceInvalidation(
       LayoutObject*,
       bool needsLayout = true);
 
   void clearInvalidationMask() { m_invalidationMask = 0; }
 
  protected:
@@ skipping 11 matching lines @@
   void markClientForInvalidation(LayoutObject*, InvalidationMode);
 
   void notifyContentChanged();
   SVGElementProxySet* elementProxySet();
 
   void willBeDestroyed() override;
 
   bool m_isInLayout;
 
  private:
+  friend class SVGTreeScopeResources;
+  // The m_registered flag is updated by SVGTreeScopeResources, and indicates
+  // that this resource is the one that is resident in the id->resource map.
+  void setRegistered(bool registered) { m_registered = registered; }
+  bool isRegistered() const { return m_registered; }
+
   friend class SVGResourcesCache;
   void addClient(LayoutObject*);
   void removeClient(LayoutObject*);
-  void detachAllClients();
 
   // Track global (markAllClientsForInvalidation) invals to avoid redundant
   // crawls.
   unsigned m_invalidationMask : 8;
 
   unsigned m_registered : 1;
   unsigned m_isInvalidating : 1;
   // 22 padding bits available
 
   HashSet<LayoutObject*> m_clients;
@@ skipping 14 matching lines @@
                                 isSVGResourceContainer());
 
 #define DEFINE_LAYOUT_SVG_RESOURCE_TYPE_CASTS(thisType, typeName)   \
   DEFINE_TYPE_CASTS(thisType, LayoutSVGResourceContainer, resource, \
                     resource->resourceType() == typeName,           \
                     resource.resourceType() == typeName)
 
 }  // namespace blink
 
 #endif