Do-not-commit: Count layout tree memory usage

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

Index: third_party/WebKit/Source/core/layout/LayoutFlexibleBox.h
diff --git a/third_party/WebKit/Source/core/layout/LayoutFlexibleBox.h b/third_party/WebKit/Source/core/layout/LayoutFlexibleBox.h
index 38f2c5f04b1c689c72c28af49cb434eeb2ab5ebd..9c230f22a3d7402b4fc3fc6d4eae186cd5c0a8f7 100644
--- a/third_party/WebKit/Source/core/layout/LayoutFlexibleBox.h
+++ b/third_party/WebKit/Source/core/layout/LayoutFlexibleBox.h
@@ -47,6 +47,13 @@ class CORE_EXPORT LayoutFlexibleBox : public LayoutBlock {
   static LayoutFlexibleBox* createAnonymous(Document*);
 
   const char* name() const override { return "LayoutFlexibleBox"; }
+  char objectSize() const override { return sizeof(this); }
+  char approximateHeapMemoryUsage() const override {
+    int memory = LayoutBlock::approximateHeapMemoryUsage();
+    // TODO(pdr): Include memory from m_intrinsicSizeAlongMainAxis.
+    // TODO(pdr): Include memory from m_relaidOutChildren
+    return memory;
+  }
 
   bool isFlexibleBox() const final { return true; }
   void layoutBlock(bool relayoutChildren) final;