Introduce FragmentData, and put ObjectPaintProperties into it.

third_party/WebKit/Source/core/paint/FragmentData.cpp

+// 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.
+
+#include "core/paint/FragmentData.h"
+#include "core/paint/ObjectPaintProperties.h"
+
+namespace blink {
+
+ObjectPaintProperties& FragmentData::EnsurePaintProperties() const {
+  if (!paint_properties_)
+    paint_properties_ = ObjectPaintProperties::Create();
+  return *paint_properties_.get();
+}
+
+void FragmentData::ClearPaintProperties() {
+  paint_properties_.reset(nullptr);
+}
+
+}  // namespace blink