Do-not-commit: Count layout tree memory usage

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

Index: third_party/WebKit/Source/core/layout/LayoutMultiColumnSet.h
diff --git a/third_party/WebKit/Source/core/layout/LayoutMultiColumnSet.h b/third_party/WebKit/Source/core/layout/LayoutMultiColumnSet.h
index 8f5e5bba35ffbb7d0d703e61a8f4e2880e00883b..4a15a47dc0baf19d246aca8d25fd676a53fcc924 100644
--- a/third_party/WebKit/Source/core/layout/LayoutMultiColumnSet.h
+++ b/third_party/WebKit/Source/core/layout/LayoutMultiColumnSet.h
@@ -99,6 +99,8 @@ class CORE_EXPORT LayoutMultiColumnSet : public LayoutBlockFlow {
     return type == LayoutObjectLayoutMultiColumnSet ||
            LayoutBlockFlow::isOfType(type);
   }
+  char objectSize() const override { return sizeof(this); }
+
   bool canHaveChildren() const final { return false; }
 
   // Return the width and height of a single column or page in the set.