Do-not-commit: Count layout tree memory usage

third_party/WebKit/Source/core/layout/LayoutBox.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2006, 2007 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 1462 matching lines @@
       LayoutUnit containerLogicalWidth);
   static void computeLogicalTopPositionedOffset(
       LayoutUnit& logicalTopPos,
       const LayoutBox* child,
       LayoutUnit logicalHeightValue,
       const LayoutBoxModelObject* containerBlock,
       LayoutUnit containerLogicalHeight);
   bool skipContainingBlockForPercentHeightCalculation(
       const LayoutBox* containingBlock) const;
 
+  char objectSize() const override { return sizeof(this); }
+  char approximateHeapMemoryUsage() const override {
+    int memory = LayoutBoxModelObject::approximateHeapMemoryUsage();
+    if (m_overflow)
+      memory += sizeof(BoxOverflowModel);
+    if (m_rareData)
+      memory += sizeof(LayoutBoxRareData);
+    return memory;
+  }
+
  private:
   void updateShapeOutsideInfoAfterStyleChange(const ComputedStyle&,
                                               const ComputedStyle* oldStyle);
   void updateGridPositionAfterStyleChange(const ComputedStyle*);
   void updateScrollSnapMappingAfterStyleChange(const ComputedStyle*,
                                                const ComputedStyle* oldStyle);
   void clearScrollSnapMapping();
   void addScrollSnapMapping();
 
   bool autoWidthShouldFitContent() const;
@@ skipping 209 matching lines @@
          breakValue == EBreakBetween::kLeft ||
          breakValue == EBreakBetween::kPage ||
          breakValue == EBreakBetween::kRecto ||
          breakValue == EBreakBetween::kRight ||
          breakValue == EBreakBetween::kVerso;
 }
 
 }  // namespace blink
 
 #endif  // LayoutBox_h