Revert of [LayoutNG] Initial implementation of NGBoxIterator

third_party/WebKit/Source/core/layout/ng/ng_box.cc

Index: third_party/WebKit/Source/core/layout/ng/ng_box.cc
diff --git a/third_party/WebKit/Source/core/layout/ng/ng_box.cc b/third_party/WebKit/Source/core/layout/ng/ng_box.cc
index 8c9a1d61d184a9fcffc94a585f63bff5a363ca5e..7f8a30fa105500bd6dd3abbdf290f4cbd5451c08 100644
--- a/third_party/WebKit/Source/core/layout/ng/ng_box.cc
+++ b/third_party/WebKit/Source/core/layout/ng/ng_box.cc
@@ -10,7 +10,7 @@
 namespace blink {
 
 NGFragment* NGBox::layout(const NGConstraintSpace& constraintSpace) {
-  NGBlockLayoutAlgorithm algorithm(style(), iterator());
+  NGBlockLayoutAlgorithm algorithm(style(), firstChild());
   return algorithm.layout(constraintSpace);
 }
 
@@ -18,4 +18,12 @@
   return m_layoutObject->style();
 }
 
+const NGBox NGBox::firstChild() const {
+  return NGBox(m_layoutObject->slowFirstChild());
+}
+
+const NGBox NGBox::nextSibling() const {
+  return NGBox(m_layoutObject->nextSibling());
+}
+
 }  // namespace blink