Improve handling of duplicate id's for SVG resources

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

 /*
  * 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 49 matching lines @@
 SVGElementProxySet* LayoutSVGResourceContainer::elementProxySet() {
   return element()->elementProxySet();
 }
 
 void LayoutSVGResourceContainer::notifyContentChanged() {
   if (SVGElementProxySet* proxySet = elementProxySet())
     proxySet->notifyContentChanged(element()->treeScope());
 }
 
 void LayoutSVGResourceContainer::willBeDestroyed() {
-  // Detach all clients referring to this resource. If the resource itself is
-  // a client, it will be detached from any such resources by the call to
-  // LayoutSVGHiddenContainer::willBeDestroyed() below.
-  detachAllClients();
-
   LayoutSVGHiddenContainer::willBeDestroyed();
-  if (!m_registered)
-    return;
   svgTreeScopeResourcesFromElement(element()).removeResource(
-      element()->getIdAttribute());
+      element()->getIdAttribute(), this);
+  DCHECK(m_clients.isEmpty());
 }
 
 void LayoutSVGResourceContainer::styleDidChange(StyleDifference diff,
                                                 const ComputedStyle* oldStyle) {
   LayoutSVGHiddenContainer::styleDidChange(diff, oldStyle);
-
-  if (m_registered)
-    return;
-  m_registered = true;
   svgTreeScopeResourcesFromElement(element()).updateResource(
       element()->getIdAttribute(), this);
 }
 
-void LayoutSVGResourceContainer::detachAllClients() {
-  const AtomicString& id = element()->getIdAttribute();
+void LayoutSVGResourceContainer::detachAllClients(const AtomicString& toId) {
+  removeAllClientsFromCache();
+
   for (auto* client : m_clients) {
     // Unlink the resource from the client's SVGResources. (The actual
     // removal will be signaled after processing all the clients.)
     SVGResources* resources =
         SVGResourcesCache::cachedResourcesForLayoutObject(client);
     // Or else the client wouldn't be in the list in the first place.
     DCHECK(resources);
     resources->resourceDestroyed(this);
 
     // Add a pending resolution based on the id of the old resource.
     Element* clientElement = toElement(client->node());
     svgTreeScopeResourcesFromElement(clientElement)
-        .addPendingResource(id, *clientElement);
+        .addPendingResource(toId, *clientElement);
   }
-
-  removeAllClientsFromCache();
+  m_clients.clear();
 }
 
 void LayoutSVGResourceContainer::idChanged(const AtomicString& oldId,
                                            const AtomicString& newId) {
-  // Invalidate all our current clients.
-  removeAllClientsFromCache();
-
-  // Remove old id, that is guaranteed to be present in cache.
-  SVGTreeScopeResources& treeScopeResources =
-      svgTreeScopeResourcesFromElement(element());
-  treeScopeResources.removeResource(oldId);
-  treeScopeResources.updateResource(newId, this);
+  svgTreeScopeResourcesFromElement(element()).updateResource(oldId, newId,
+                                                             this);
 }
 
 void LayoutSVGResourceContainer::markAllClientsForInvalidation(
     InvalidationMode mode) {
   if (m_isInvalidating)
     return;
   SVGElementProxySet* proxySet = elementProxySet();
   if (m_clients.isEmpty() && (!proxySet || proxySet->isEmpty()))
     return;
   if (m_invalidationMask & mode)
@@ skipping 138 matching lines @@
       // This will process the rest of the ancestors.
       toLayoutSVGResourceContainer(current)->removeAllClientsFromCache();
       break;
     }
 
     current = current->parent();
   }
 }
 
 }  // namespace blink