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

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

Index: third_party/WebKit/Source/core/html/HTMLOptGroupElement.h
diff --git a/third_party/WebKit/Source/core/html/HTMLOptGroupElement.h b/third_party/WebKit/Source/core/html/HTMLOptGroupElement.h
index ee28433a35d4592aa5367ebfe35c97373afe9221..cb4fdc6c62d09f10522ddcd1949c5c1fa043ae13 100644
--- a/third_party/WebKit/Source/core/html/HTMLOptGroupElement.h
+++ b/third_party/WebKit/Source/core/html/HTMLOptGroupElement.h
@@ -55,21 +55,13 @@ class CORE_EXPORT HTMLOptGroupElement final : public HTMLElement {
                       const AtomicString&) override;
   void accessKeyAction(bool sendMouseEvents) override;
   void didAddUserAgentShadowRoot(ShadowRoot&) override;
-  void attachLayoutTree(const AttachContext& = AttachContext()) override;
-  void detachLayoutTree(const AttachContext& = AttachContext()) override;
   bool matchesEnabledPseudoClass() const override;
   InsertionNotificationRequest insertedInto(ContainerNode*) override;
   void removedFrom(ContainerNode*) override;
 
-  // <optgroup> might not have a layoutObject so we manually manage a cached
-  // style.
-  void updateNonComputedStyle();
-  ComputedStyle* nonLayoutObjectComputedStyle() const override;
   PassRefPtr<ComputedStyle> customStyleForLayoutObject() override;
 
   void updateGroupLabel();
-
-  RefPtr<ComputedStyle> m_style;
 };
 
 }  // namespace blink