Don't register excessive pending SVG resources

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 13 matching lines @@
 #include "core/layout/svg/LayoutSVGResourceFilter.h"
 #include "core/layout/svg/LayoutSVGResourceMasker.h"
 #include "core/layout/svg/SVGResources.h"
 #include "core/layout/svg/SVGResourcesCache.h"
 #include "core/paint/DeprecatedPaintLayer.h"
 
 #include "wtf/TemporaryChange.h"
 
 namespace blink {
 
-static inline SVGDocumentExtensions& svgExtensionsFromElement(SVGElement* element)
+static inline SVGDocumentExtensions& svgExtensionsFromElement(Element* element)
 {
     ASSERT(element);
     return element->document().accessSVGExtensions();
 }
 
 LayoutSVGResourceContainer::LayoutSVGResourceContainer(SVGElement* node)
     : LayoutSVGHiddenContainer(node)
     , m_isInLayout(false)
     , m_id(node->getIdAttribute())
     , m_invalidationMask(0)
@@ skipping 16 matching lines @@
 
     TemporaryChange<bool> inLayoutChange(m_isInLayout, true);
 
     LayoutSVGHiddenContainer::layout();
 
     clearInvalidationMask();
 }
 
 void LayoutSVGResourceContainer::willBeDestroyed()
 {
-    SVGResourcesCache::resourceDestroyed(this);
+    // 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)
         svgExtensionsFromElement(element()).removeResource(m_id);
 }
 
 void LayoutSVGResourceContainer::styleDidChange(StyleDifference diff, const ComputedStyle* oldStyle)
 {
     LayoutSVGHiddenContainer::styleDidChange(diff, oldStyle);
 
     if (!m_registered) {
         m_registered = true;
         registerResource();
     }
 }
 
+void LayoutSVGResourceContainer::detachAllClients()
+{
+    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);
+        ASSERT(resources); // Or else the client wouldn't be in the list in the first place.
+        resources->resourceDestroyed(this);
+
+        // Add a pending resolution based on the id of the old resource.
+        Element* clientElement = toElement(client->node());
+        svgExtensionsFromElement(clientElement).addPendingResource(m_id, clientElement);
+    }
+
+    removeAllClientsFromCache();
+}
+
 void LayoutSVGResourceContainer::idChanged()
 {
     // Invalidate all our current clients.
     removeAllClientsFromCache();
 
     // Remove old id, that is guaranteed to be present in cache.
     SVGDocumentExtensions& extensions = svgExtensionsFromElement(element());
     extensions.removeResource(m_id);
     m_id = element()->getIdAttribute();
 
@@ skipping 196 matching lines @@
             // This will process the rest of the ancestors.
             toLayoutSVGResourceContainer(current)->removeAllClientsFromCache();
             break;
         }
 
         current = current->parent();
     }
 }
 
 }