[LayoutNG] Add NGLayoutInputNode::ShowNodeTree

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

Index: third_party/WebKit/Source/core/layout/ng/ng_block_node.cc
diff --git a/third_party/WebKit/Source/core/layout/ng/ng_block_node.cc b/third_party/WebKit/Source/core/layout/ng/ng_block_node.cc
index 64f785b12f7dbd4f6205fdd8f32bba15cc331ad6..1b706adf10b08d7e4de9878e69ab10c787d34784 100644
--- a/third_party/WebKit/Source/core/layout/ng/ng_block_node.cc
+++ b/third_party/WebKit/Source/core/layout/ng/ng_block_node.cc
@@ -218,7 +218,7 @@ NGLayoutInputNode* NGBlockNode::NextSibling() {
   return next_sibling_;
 }
 
-LayoutObject* NGBlockNode::GetLayoutObject() {
+LayoutObject* NGBlockNode::GetLayoutObject() const {
   return layout_box_;
 }
 
@@ -276,6 +276,11 @@ bool NGBlockNode::CanUseNewLayout() {
   return RuntimeEnabledFeatures::layoutNGEnabled();
 }
 
+String NGBlockNode::ToString() const {
+  return String::Format("NGBlockNode: '%s'",
+                        GetLayoutObject()->DebugName().Ascii().data());
+}
+
 void NGBlockNode::CopyFragmentDataToLayoutBox(
     const NGConstraintSpace& constraint_space,
     NGLayoutResult* layout_result) {