Introduce FragmentData, and put ObjectPaintProperties into it.

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

Index: third_party/WebKit/Source/core/paint/RarePaintData.h
diff --git a/third_party/WebKit/Source/core/paint/RarePaintData.h b/third_party/WebKit/Source/core/paint/RarePaintData.h
index a80ac6daeff0460d5f2406d6a6b8347b67147bf2..93534730cfc7076b6d4e194f32808b4fe02df134 100644
--- a/third_party/WebKit/Source/core/paint/RarePaintData.h
+++ b/third_party/WebKit/Source/core/paint/RarePaintData.h
@@ -6,13 +6,13 @@
 #define RarePaintData_h
 
 #include "core/CoreExport.h"
+#include "core/paint/FragmentData.h"
 #include "platform/wtf/Allocator.h"
 #include "platform/wtf/Noncopyable.h"
 
 namespace blink {
 
 class PropertyTreeState;
-class ObjectPaintProperties;
 class PaintLayer;
 
 // This is for paint-related data on LayoutObject that is not needed on all
@@ -28,11 +28,15 @@ class CORE_EXPORT RarePaintData {
   PaintLayer* Layer() { return layer_.get(); }
   void SetLayer(std::unique_ptr<PaintLayer>);
 
+  FragmentData* Fragment() const { return fragment_data_.get(); }
+
+  FragmentData& EnsureFragment();
+
   ObjectPaintProperties* PaintProperties() const {
-    return paint_properties_.get();
+    if (fragment_data_)
+      return fragment_data_->PaintProperties();
+    return nullptr;
   }
-  ObjectPaintProperties& EnsurePaintProperties();
-  void ClearPaintProperties();
 
   PropertyTreeState* LocalBorderBoxProperties() const {
     return local_border_box_properties_.get();
@@ -52,8 +56,7 @@ class CORE_EXPORT RarePaintData {
   // depending on the return value of LayoutBoxModelObject::layerTypeRequired().
   std::unique_ptr<PaintLayer> layer_;
 
-  // Holds references to the paint property nodes created by this object.
-  std::unique_ptr<ObjectPaintProperties> paint_properties_;
+  std::unique_ptr<FragmentData> fragment_data_;
 
   // 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