Move RarePaintData to its own file

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

+// Copyright 2017 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 RarePaintData_h
+#define RarePaintData_h
+
+#include "core/CoreExport.h"
+#include "wtf/Allocator.h"
+#include "wtf/Noncopyable.h"
+
+namespace blink {
+
+class PropertyTreeState;
+class ObjectPaintProperties;
+
+// This is for paint-related data on LayoutObject that is not needed on all
+// objects.
+// TODO(pdr): Store LayoutBoxModelObject's m_paintLayer in this structure.
+class CORE_EXPORT RarePaintData {
+  WTF_MAKE_NONCOPYABLE(RarePaintData);
+  USING_FAST_MALLOC(RarePaintData);
+
+ public:
+  RarePaintData();
+  ~RarePaintData();
+
+  ObjectPaintProperties* paintProperties() const {
+    return m_paintProperties.get();
+  }
+  ObjectPaintProperties& ensurePaintProperties();
+
+  PropertyTreeState* localBorderBoxProperties() const {
+    return m_localBorderBoxProperties.get();
+  }
+
+  void clearLocalBorderBoxProperties();
+  void setLocalBorderBoxProperties(PropertyTreeState&);
+  const PropertyTreeState* contentsProperties() const;
+
+ private:
+  // Holds references to the paint property nodes created by this object.
+  std::unique_ptr<ObjectPaintProperties> m_paintProperties;
+
+  // This is a complete set of property nodes that should be used as a
+  // starting point to paint a LayoutObject. This data is cached because some
+  // properties inherit from the containing block chain instead of the
+  // painting parent and cannot be derived in O(1) during the paint walk.
+  //
+  // For example: <div style='opacity: 0.3;'/>
+  //   The div's local border box properties would have an opacity 0.3 effect
+  //   node. Even though the div has no transform, its local border box
+  //   properties would have a transform node that points to the div's
+  //   ancestor transform space.
+  std::unique_ptr<PropertyTreeState> m_localBorderBoxProperties;
+
+  // This is the complete set of property nodes that can be used to paint the
+  // contents of this object. It is similar to m_localBorderBoxProperties but
+  // includes properties (e.g., overflow clip, scroll translation) that apply
+  // to contents. This cached value is derived from m_localBorderBoxProperties
+  // and m_paintProperties and should be invalidated when these change.
+  mutable std::unique_ptr<PropertyTreeState> m_contentsProperties;
+};
+
+}  // namespace blink
+
+#endif