Do-not-commit: Count layout tree memory usage

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2003-2013 Apple Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
@@ skipping 331 matching lines @@
       return child.y() + marginBeforeForChild(*child.layoutObject());
 
     return child.y() + child.layoutObject()->marginTop();
   }
 
   LayoutPoint flipFloatForWritingModeForChild(const FloatingObject&,
                                               const LayoutPoint&) const;
 
   const char* name() const override { return "LayoutBlockFlow"; }
 
+  char objectSize() const override { return sizeof(this); }
+  char approximateHeapMemoryUsage() const override {
+    int memory = LayoutBlock::approximateHeapMemoryUsage();
+    if (m_rareData)
+      memory += sizeof(LayoutBlockFlowRareData);
+    if (m_floatingObjects)
+      memory += sizeof(FloatingObjects);
+    return memory;
+  }
+
   FloatingObject* insertFloatingObject(LayoutBox&);
 
   // Position and lay out all floats that have not yet been positioned.
   //
   // This will mark them as "placed", which means that they have found their
   // final location in this layout pass.
   //
   // |logicalTopMarginEdge| is the minimum logical top for the floats. The
   // final logical top of the floats will also be affected by clearance and
   // space available after having positioned earlier floats.
@@ skipping 593 matching lines @@
   void positionDialog();
 
   // END METHODS DEFINED IN LayoutBlockFlowLine
 };
 
 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutBlockFlow, isLayoutBlockFlow());
 
 }  // namespace blink
 
 #endif  // LayoutBlockFlow_h