Support display: contents for elements, first-line and first-letter pseudos.

third_party/WebKit/Source/core/html/HTMLOptGroupElement.cpp

Index: third_party/WebKit/Source/core/html/HTMLOptGroupElement.cpp
diff --git a/third_party/WebKit/Source/core/html/HTMLOptGroupElement.cpp b/third_party/WebKit/Source/core/html/HTMLOptGroupElement.cpp
index de290bccc9bfb438b609e4634474d4351cb082bf..44fcac7a3d7f56d55de14866a12b1950ded6c86b 100644
--- a/third_party/WebKit/Source/core/html/HTMLOptGroupElement.cpp
+++ b/third_party/WebKit/Source/core/html/HTMLOptGroupElement.cpp
@@ -68,19 +68,6 @@ void HTMLOptGroupElement::parseAttribute(const QualifiedName& name,
   }
 }
 
-void HTMLOptGroupElement::attachLayoutTree(const AttachContext& context) {
-  if (context.resolvedStyle) {
-    DCHECK(!m_style || m_style == context.resolvedStyle);
-    m_style = context.resolvedStyle;
-  }
-  HTMLElement::attachLayoutTree(context);
-}
-
-void HTMLOptGroupElement::detachLayoutTree(const AttachContext& context) {
-  m_style.clear();
-  HTMLElement::detachLayoutTree(context);
-}
-
 bool HTMLOptGroupElement::supportsFocus() const {
   HTMLSelectElement* select = ownerSelectElement();
   if (select && select->usesMenuList())
@@ -110,21 +97,16 @@ void HTMLOptGroupElement::removedFrom(ContainerNode* insertionPoint) {
   HTMLElement::removedFrom(insertionPoint);
 }
 
-void HTMLOptGroupElement::updateNonComputedStyle() {
-  m_style = originalStyleForLayoutObject();
+PassRefPtr<ComputedStyle> HTMLOptGroupElement::customStyleForLayoutObject() {
+  RefPtr<ComputedStyle> style = originalStyleForLayoutObject();
+  storeNonLayoutObjectComputedStyle(style);
+
   if (layoutObject()) {
     if (HTMLSelectElement* select = ownerSelectElement())
       select->updateListOnLayoutObject();
   }
-}
 
-ComputedStyle* HTMLOptGroupElement::nonLayoutObjectComputedStyle() const {
-  return m_style.get();
-}
-
-PassRefPtr<ComputedStyle> HTMLOptGroupElement::customStyleForLayoutObject() {
-  updateNonComputedStyle();
-  return m_style;
+  return std::move(style);
 }
 
 String HTMLOptGroupElement::groupLabelText() const {