DOM-based SVG resource tracking

third_party/WebKit/Source/core/layout/svg/SVGResources.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 139 matching lines @@
 template <>
 bool IsResourceOfType<LayoutSVGResourceContainer>(
     LayoutSVGResourceContainer* container) {
   return true;
 }
 
 template <typename ContainerType>
 ContainerType* AttachToResource(SVGTreeScopeResources& tree_scope_resources,
                                 const AtomicString& id,
                                 SVGElement& element) {
-  if (LayoutSVGResourceContainer* container =
-          tree_scope_resources.ResourceById(id)) {
+  SVGTreeScopeResources::Resource* resource =
+      tree_scope_resources.ResourceForId(id);
+  if (!resource)
+    return nullptr;
+  if (LayoutSVGResourceContainer* container = resource->ResourceContainer()) {
     if (IsResourceOfType<ContainerType>(container))
       return static_cast<ContainerType*>(container);
   }
-  tree_scope_resources.AddPendingResource(id, element);
+  resource->AddWatch(element);
   return nullptr;
 }
 }
 
 bool SVGResources::HasResourceData() const {
   return clipper_filter_masker_data_ || marker_data_ || fill_stroke_data_ ||
          linked_resource_;
 }
 
 static inline SVGResources& EnsureResources(
@@ skipping 96 matching lines @@
     AtomicString id = TargetReferenceFromResource(element);
     EnsureResources(resources).SetLinkedResource(
         AttachToResource<LayoutSVGResourceContainer>(tree_scope_resources, id,
                                                      element));
   }
 
   return (!resources || !resources->HasResourceData()) ? nullptr
                                                        : std::move(resources);
 }
 
+void SVGResources::RemoveUnreferencedResources(const LayoutObject& object) {
+  SVGTreeScopeResources& tree_scope_resources =
+      ToSVGElement(*object.GetNode())
+          .TreeScopeForIdResolution()
+          .EnsureSVGTreeScopedResources();
+  tree_scope_resources.RemoveUnreferencedResources();
+}
+
+void SVGResources::RemoveWatchesForElement(Element& element) {
+  SECURITY_DCHECK(element.IsSVGElement());
+  SVGElement& svg_element = ToSVGElement(element);
+  SVGTreeScopeResources& tree_scope_resources =
+      svg_element.TreeScopeForIdResolution().EnsureSVGTreeScopedResources();
+  tree_scope_resources.RemoveWatchesForElement(svg_element);
+}
+
 void SVGResources::LayoutIfNeeded() {
   if (clipper_filter_masker_data_) {
     if (LayoutSVGResourceClipper* clipper =
             clipper_filter_masker_data_->clipper)
       clipper->LayoutIfNeeded();
     if (LayoutSVGResourceMasker* masker = clipper_filter_masker_data_->masker)
       masker->LayoutIfNeeded();
     if (LayoutSVGResourceFilter* filter = clipper_filter_masker_data_->filter)
       filter->LayoutIfNeeded();
   }
@@ skipping 362 matching lines @@
               stroke->GetElement());
   }
 
   if (linked_resource_)
     fprintf(stderr, " |-> xlink:href : %p (node=%p)\n", linked_resource_,
             linked_resource_->GetElement());
 }
 #endif
 
 }  // namespace blink