Tracking filter mutation via SVGElementProxy

third_party/WebKit/Source/core/svg/SVGResourceClient.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef SVGResourceClient_h
 #define SVGResourceClient_h
 
 #include "core/CoreExport.h"
-#include "core/fetch/DocumentResource.h"
-#include "core/svg/SVGFilterElement.h"
 #include "platform/heap/Handle.h"
 
 namespace blink {
 
-class Document;
-class FilterOperations;
+class SVGElementProxy;
 
-class CORE_EXPORT SVGResourceClient : public DocumentResourceClient {
-  USING_PRE_FINALIZER(SVGResourceClient, clearFilterReferences);
+class CORE_EXPORT SVGResourceClient : public GarbageCollectedMixin {
+ public:
+  virtual ~SVGResourceClient() {}
 
- public:
-  SVGResourceClient();
-  ~SVGResourceClient() override;
-  void addFilterReferences(const FilterOperations&, const Document&);
-  void clearFilterReferences();
+  virtual void resourceContentChanged(SVGElementProxy*) = 0;
+  virtual void resourceReferenceChanged(SVGElementProxy*) = 0;

[pdr., 2016/10/20 03:11:05]

Are the SVGElementProxy* arguments needed? Would it be safe to use them since
the proxy could be freed when this is called?

[fs, 2016/10/20 11:28:00]

I guess they aren't strictly needed (yet. Will be if/when a client is registered
- and cares about - multiple proxies.)

I can drop them for now.

They are safe because the reference is GCd and on the stack.

 
-  virtual void filterNeedsInvalidation() = 0;
+  DEFINE_INLINE_VIRTUAL_TRACE() {}
 
-  void filterWillBeDestroyed(SVGFilterElement*);
-
-  void notifyFinished(Resource*) override;
-  String debugName() const override { return "SVGResourceClient"; }
-
-  DECLARE_TRACE();
-
- private:
-  HeapHashSet<WeakMember<SVGFilterElement>> m_internalFilterReferences;
-  HeapVector<Member<DocumentResource>> m_externalFilterReferences;
+ protected:
+  SVGResourceClient() {}
 };
 
 }  // namespace blink
 
 #endif  // SVGResourceClient_h