Reuse existing paint property node is possible

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

 // Copyright 2015 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 PaintPropertyTreeBuilder_h
 #define PaintPropertyTreeBuilder_h
 
 #include "platform/geometry/LayoutPoint.h"
 #include "platform/graphics/paint/ClipPaintPropertyNode.h"
 #include "platform/graphics/paint/EffectPaintPropertyNode.h"
 #include "platform/graphics/paint/TransformPaintPropertyNode.h"
 #include "wtf/RefPtr.h"
 
 namespace blink {
 
 class FrameView;
 class LayoutObject;
+class ObjectPaintProperties;
 
 // The context for PaintPropertyTreeBuilder.
 // It's responsible for bookkeeping tree state in other order, for example, the most recent
 // position container seen.
 struct PaintPropertyTreeBuilderContext {
     // State that propagates on the containing block chain (and so is adjusted
     // when an absolute or fixed position object is encountered).
     struct ContainingBlockContext {
         // The combination of a transform and paint offset describes a linear space.
         // When a layout object recur to its children, the main context is expected to refer
@@ skipping 32 matching lines @@
 // Special things include but not limit to: overflow clip, transform, fixed-pos, animation,
 // mask, filter, ... etc.
 // It expects to be invoked for each layout tree node in DOM order during InPrePaint phase.
 class PaintPropertyTreeBuilder {
 public:
     void buildTreeRootNodes(FrameView&, PaintPropertyTreeBuilderContext&);
     void buildTreeNodes(FrameView&, PaintPropertyTreeBuilderContext&);
     void buildTreeNodes(const LayoutObject&, PaintPropertyTreeBuilderContext&);
 
 private:
+    template <typename PropertyNode, void (ObjectPaintProperties::*Setter)(PassRefPtr<PropertyNode>)>
+    static void clearPaintProperty(const LayoutObject&);
+
+    template <
+        typename PropertyNode,
+        PropertyNode* (ObjectPaintProperties::*Getter)() const,
+        void (ObjectPaintProperties::*Setter)(PassRefPtr<PropertyNode>),
+        typename... Args>
+    static void updateOrCreatePaintProperty(const LayoutObject&, const PaintPropertyTreeBuilderContext&, PropertyNode*& contextProperty, const Args&...);
+
     static void updatePaintOffsetTranslation(const LayoutObject&, PaintPropertyTreeBuilderContext&);
     static void updateTransform(const LayoutObject&, PaintPropertyTreeBuilderContext&);
     static void updateEffect(const LayoutObject&, PaintPropertyTreeBuilderContext&);
     static void updateCssClip(const LayoutObject&, PaintPropertyTreeBuilderContext&);
     static void updateLocalBorderBoxContext(const LayoutObject&, const PaintPropertyTreeBuilderContext&);
     static void updateScrollbarPaintOffset(const LayoutObject&, const PaintPropertyTreeBuilderContext&);
     static void updateOverflowClip(const LayoutObject&, PaintPropertyTreeBuilderContext&);
     static void updatePerspective(const LayoutObject&, PaintPropertyTreeBuilderContext&);
     static void updateSvgLocalToBorderBoxTransform(const LayoutObject&, PaintPropertyTreeBuilderContext&);
     static void updateScrollTranslation(const LayoutObject&, PaintPropertyTreeBuilderContext&);
     static void updateOutOfFlowContext(const LayoutObject&, PaintPropertyTreeBuilderContext&);
 };
 
 } // namespace blink
 
 #endif // PaintPropertyTreeBuilder_h