Do-not-commit: Count layout tree memory usage

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

Index: third_party/WebKit/Source/core/layout/LayoutBlockFlow.h
diff --git a/third_party/WebKit/Source/core/layout/LayoutBlockFlow.h b/third_party/WebKit/Source/core/layout/LayoutBlockFlow.h
index ecc82710c737c1dde65884cbf6f5d4460d93076d..1c4305bd31414fc9dba776a82ec184733b555657 100644
--- a/third_party/WebKit/Source/core/layout/LayoutBlockFlow.h
+++ b/third_party/WebKit/Source/core/layout/LayoutBlockFlow.h
@@ -349,6 +349,16 @@ class CORE_EXPORT LayoutBlockFlow : public LayoutBlock {
 
   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.