[LayoutNG] Switch NGConstraintSpace to being RefCounted.

third_party/WebKit/Source/core/layout/ng/ng_constraint_space.h

 // Copyright 2016 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 NGConstraintSpace_h
 #define NGConstraintSpace_h
 
 #include "core/CoreExport.h"
 #include "core/layout/ng/ng_units.h"
 #include "core/layout/ng/ng_writing_mode.h"
-#include "platform/heap/Handle.h"
 #include "wtf/Optional.h"
+#include "wtf/RefCounted.h"
 #include "wtf/text/WTFString.h"
 
 namespace blink {
 
 class LayoutBox;
 class NGBoxFragment;
 
 enum NGFragmentationType {
   kFragmentNone,
   kFragmentPage,
   kFragmentColumn,
   kFragmentRegion
 };
 
 // The NGConstraintSpace represents a set of constraints and available space
 // which a layout algorithm may produce a NGFragment within.
 class CORE_EXPORT NGConstraintSpace final
-    : public GarbageCollectedFinalized<NGConstraintSpace> {
+    : public RefCounted<NGConstraintSpace> {
  public:
   // This should live on NGBlockNode or another layout bridge and probably take
   // a root NGConstraintSpace.
-  static NGConstraintSpace* CreateFromLayoutObject(const LayoutBox&);
+  static RefPtr<NGConstraintSpace> CreateFromLayoutObject(const LayoutBox&);
 
   const std::shared_ptr<NGExclusions>& Exclusions() const {
     return exclusions_;
   }
 
   TextDirection Direction() const {
     return static_cast<TextDirection>(direction_);
   }
 
   NGWritingMode WritingMode() const {
@@ skipping 69 matching lines @@
   void Subtract(const NGBoxFragment*);
 
   NGMarginStrut MarginStrut() const { return margin_strut_; }
 
   NGLogicalOffset BfcOffset() const { return bfc_offset_; }
 
   WTF::Optional<LayoutUnit> ClearanceOffset() const {
     return clearance_offset_;
   }
 
-  DEFINE_INLINE_VIRTUAL_TRACE() {}
-
   String ToString() const;
 
  private:
   friend class NGConstraintSpaceBuilder;
   // Default constructor.
   NGConstraintSpace(NGWritingMode,
                     TextDirection,
                     NGLogicalSize available_size,
                     NGLogicalSize percentage_resolution_size,
                     NGPhysicalSize initial_containing_block_size,
@@ skipping 47 matching lines @@
 };
 
 inline std::ostream& operator<<(std::ostream& stream,
                                 const NGConstraintSpace& value) {
   return stream << value.ToString();
 }
 
 }  // namespace blink
 
 #endif  // NGConstraintSpace_h