Move LayoutObject to satellite NodeLayoutData that hangs from a Node.

third_party/WebKit/Source/core/dom/Node.cpp

Index: third_party/WebKit/Source/core/dom/Node.cpp
diff --git a/third_party/WebKit/Source/core/dom/Node.cpp b/third_party/WebKit/Source/core/dom/Node.cpp
index e7d6f098551ae1870c005465e4180553085f1d3f..9dce05438d3d369adcb0ed898ba39b2b781883c8 100644
--- a/third_party/WebKit/Source/core/dom/Node.cpp
+++ b/third_party/WebKit/Source/core/dom/Node.cpp
@@ -298,6 +298,8 @@ Node::~Node() {
   // With Oilpan, the rare data finalizer also asserts for
   // this condition (we cannot directly access it here.)
   CHECK(HasRareData() || !GetLayoutObject());

[esprehn, 2017/04/13 22:02:49]

You can remove this CHECK and the comment now, the assert is handled inside
~NodeLayoutData.

[nainar, 2017/04/13 22:28:16]

Done.

+  if (!HasRareData() && !data_.node_layout_data_->IsSharedEmptyData())
+    delete data_.node_layout_data_;
   InstanceCounters::DecrementNodeCounter();
 }
 
@@ -311,9 +313,9 @@ NodeRareData& Node::EnsureRareData() {
     return *RareData();
 
   if (IsElementNode())
-    data_.rare_data_ = ElementRareData::Create(data_.layout_object_);
+    data_.rare_data_ = ElementRareData::Create(data_.node_layout_data_);
   else
-    data_.rare_data_ = NodeRareData::Create(data_.layout_object_);
+    data_.rare_data_ = NodeRareData::Create(data_.node_layout_data_);
 
   DCHECK(data_.rare_data_);
   SetFlag(kHasRareDataFlag);
@@ -589,6 +591,30 @@ LayoutBox* Node::GetLayoutBox() const {
                                                  : nullptr;
 }
 
+void Node::SetLayoutObject(LayoutObject* layout_object) {
+  NodeLayoutData* node_layout_data = HasRareData()
+                                         ? data_.rare_data_->GetNodeLayoutData()
+                                         : data_.node_layout_data_;
+
+  // Already pointing to a non empty NodeLayoutData so just set the pointer to
+  // // the new LayoutObject.

[esprehn, 2017/04/13 22:02:49]

extra //

[nainar, 2017/04/13 22:28:16]

I can't even. git cl format broke this I guess. Done. 

+  if (!node_layout_data->IsSharedEmptyData()) {
+    node_layout_data->SetLayoutObject(layout_object);
+    return;
+  }
+
+  if (!layout_object)
+    return;
+
+  // Swap the NodeLayoutData to point to a new NodeLayoutData instead of the //

[esprehn, 2017/04/13 22:02:49]

extra //

[nainar, 2017/04/13 22:28:16]

Done. 

+  // static SharedEmptyData instance.
+  node_layout_data = new NodeLayoutData(layout_object);
+  if (HasRareData())
+    data_.rare_data_->SetNodeLayoutData(node_layout_data);
+  else
+    data_.node_layout_data_ = node_layout_data;
+}
+
 LayoutBoxModelObject* Node::GetLayoutBoxModelObject() const {
   LayoutObject* layout_object = this->GetLayoutObject();
   return layout_object && layout_object->IsBoxModelObject()