Storage of ComputedStyle separate from LayoutObject.

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 9565e1f766926b92b9cf56ffaf5b471310b59f08..cefce86da630022ab2b72b615f1d7230a09b6452 100644
--- a/third_party/WebKit/Source/core/dom/Node.cpp
+++ b/third_party/WebKit/Source/core/dom/Node.cpp
@@ -592,6 +592,67 @@ bool Node::isEditableToAccessibility(EditableLevel editableLevel) const
     return false;
 }
 
+void Node::setLayoutObject(LayoutObject* layoutObject)
+{
+    DCHECK(!layoutObject->style() || layoutObject->style() == computedStyle());
+    // this will probably cause a crash because of the <option> case
+    // if (layoutObject)
+        // layoutObject->setStyleInternal(computedStyle());
+    if (hasRareData()) {
+        if (hasLayoutObject()) {
+            if (this->layoutObject()->style()) {
+                if (layoutObject) {
+                    layoutObject->setStyleInternal(this->layoutObject()->mutableStyle());
+                } else {
+                    m_data.m_rareData->setComputedStyle(this->layoutObject()->mutableStyle());
+                }
+            }
+        } else if (m_data.m_rareData->computedStyle() && layoutObject) {
+            layoutObject->setStyleInternal(m_data.m_rareData->computedStyle());
+            m_data.m_rareData->setComputedStyle(nullptr);
+        }
+        m_data.m_rareData->setLayoutObject(layoutObject);
+    } else {
+        if (hasLayoutObject()) {
+            if (this->layoutObject()->style()) {
+                if (layoutObject) {
+                    layoutObject->setStyleInternal(this->layoutObject()->mutableStyle());
+                    m_data.m_layoutObject = layoutObject;
+                } else {
+                    m_data.m_computedStyle = this->layoutObject()->mutableStyle();
+                }
+            } else {
+                m_data.m_layoutObject = layoutObject;
+            }
+        } else {
+            if (m_data.m_computedStyle && layoutObject) {
+                layoutObject->setStyleInternal(m_data.m_computedStyle);
+            }
+            m_data.m_layoutObject = layoutObject;
+        }
+        // if (!(hasLayoutObject() && this->layoutObject()->style() && !layoutObject))
+        //     m_data.m_layoutObject = layoutObject;
+    }
+
+    if (layoutObject) {
+        setFlag(HasLayoutObjectFlag);
+    } else {
+        clearFlag(HasLayoutObjectFlag);
+    }
+}
+
+void Node::clearStyleAndLayoutObject()
+{
+    if (hasRareData()) {
+        m_data.m_rareData->setLayoutObject(nullptr);
+        m_data.m_rareData->setComputedStyle(nullptr);
+    } else {
+        // Will nullify the data regardless of whether it is a LayoutObject or a ComputedStyle
+        m_data.m_layoutObject = nullptr;
+    }
+    clearFlag(HasLayoutObjectFlag);
+}
+
 LayoutBox* Node::layoutBox() const
 {
     LayoutObject* layoutObject = this->layoutObject();
@@ -931,7 +992,7 @@ void Node::detach(const AttachContext& context)
 
     if (layoutObject())
         layoutObject()->destroyAndCleanupAnonymousWrappers();
-    setLayoutObject(nullptr);
+    clearStyleAndLayoutObject();
     setStyleChange(NeedsReattachStyleChange);
     clearChildNeedsStyleInvalidation();
 }