Use an SVGElementProxy in ReferenceClipPathOperation

third_party/WebKit/Source/core/paint/PaintLayerResourceInfo.h

 /*
  * Copyright (C) 2012 Adobe Systems Incorporated. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1. Redistributions of source code must retain the above
  *    copyright notice, this list of conditions and the following
  *    disclaimer.
  * 2. Redistributions in binary form must reproduce the above
  *    copyright notice, this list of conditions and the following
  *    disclaimer in the documentation and/or other materials
  *    provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER "AS IS" AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE
  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
  * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
  * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
 
-#ifndef PaintLayerFilterInfo_h
-#define PaintLayerFilterInfo_h
+#ifndef PaintLayerResourceInfo_h
+#define PaintLayerResourceInfo_h
 
 #include "core/svg/SVGResourceClient.h"
 #include "platform/heap/Handle.h"
 #include "wtf/Noncopyable.h"
 
 namespace blink {
 
 class FilterEffect;
 class PaintLayer;
 
-// PaintLayerFilterInfo holds the filter information for painting.
-// https://drafts.fxtf.org/filters/
+// PaintLayerResourceInfo holds the filter information for painting
+// https://drafts.fxtf.org/filters/. It also acts as the resource client for
+// change notifications from <clipPath> elements for the clip-path property.
 //
 // Because PaintLayer is not allocated for SVG objects, SVG filters (both
 // software and hardware-accelerated) use a different code path to paint the
 // filters (SVGFilterPainter), but both code paths use the same abstraction for
 // painting non-hardware accelerated filters (FilterEffect). Hardware
 // accelerated CSS filters use CompositorFilterOperations, that is backed by cc.
-//
-class PaintLayerFilterInfo final
-    : public GarbageCollectedFinalized<PaintLayerFilterInfo>,
+class PaintLayerResourceInfo final
+    : public GarbageCollectedFinalized<PaintLayerResourceInfo>,
       public SVGResourceClient {
-  WTF_MAKE_NONCOPYABLE(PaintLayerFilterInfo);
-  USING_GARBAGE_COLLECTED_MIXIN(PaintLayerFilterInfo);
+  WTF_MAKE_NONCOPYABLE(PaintLayerResourceInfo);
+  USING_GARBAGE_COLLECTED_MIXIN(PaintLayerResourceInfo);
 
  public:
-  explicit PaintLayerFilterInfo(PaintLayer*);
-  ~PaintLayerFilterInfo() override;
+  explicit PaintLayerResourceInfo(PaintLayer*);
+  ~PaintLayerResourceInfo() override;
 
   void setLastEffect(FilterEffect*);
   FilterEffect* lastEffect() const;
   void invalidateFilterChain();
 
   void clearLayer() { m_layer = nullptr; }
 
   TreeScope* treeScope() override;
 
   void resourceContentChanged() override;
   void resourceElementChanged() override;
 
   DECLARE_TRACE();
 
  private:
   // |clearLayer| must be called before *m_layer becomes invalid.
   PaintLayer* m_layer;
   Member<FilterEffect> m_lastEffect;
 };
 
 }  // namespace blink
 
-#endif  // PaintLayerFilterInfo_h
+#endif  // PaintLayerResourceInfo_h