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

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2010 Apple Inc. All rights
  * reserved.
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 57 matching lines @@
   HTMLElement::parseAttribute(params);
 
   if (params.name == disabledAttr) {
     pseudoStateChanged(CSSSelector::PseudoDisabled);
     pseudoStateChanged(CSSSelector::PseudoEnabled);
   } else if (params.name == labelAttr) {
     updateGroupLabel();
   }
 }
 
-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())
     return false;
   return HTMLElement::supportsFocus();
 }
 
 bool HTMLOptGroupElement::matchesEnabledPseudoClass() const {
   return !isDisabledFormControl();
 }
 
 Node::InsertionNotificationRequest HTMLOptGroupElement::insertedInto(
     ContainerNode* insertionPoint) {
   HTMLElement::insertedInto(insertionPoint);
   if (HTMLSelectElement* select = ownerSelectElement()) {
     if (insertionPoint == select)
       select->optGroupInsertedOrRemoved(*this);
   }
   return InsertionDone;
 }
 
 void HTMLOptGroupElement::removedFrom(ContainerNode* insertionPoint) {
   if (isHTMLSelectElement(*insertionPoint)) {
     if (!parentNode())
       toHTMLSelectElement(insertionPoint)->optGroupInsertedOrRemoved(*this);
   }
   HTMLElement::removedFrom(insertionPoint);
 }
 
-void HTMLOptGroupElement::updateNonComputedStyle() {
-  m_style = originalStyleForLayoutObject();
-  if (layoutObject()) {
+void HTMLOptGroupElement::willRecalcStyle(StyleRecalcChange change) {
+  if (layoutObject() && (change >= IndependentInherit || needsStyleRecalc())) {

[rune, 2017/01/27 13:09:23]

I don't think I understand this test completely. Also, didRecalcStyle() sounds
intuitively more correct, but "change" is modified, so I guess it can be
explained by the if-test?

[emilio, 2017/01/27 22:13:15]

These were the conditions that gated the customStyleForLayoutObject() call, so I
wanted to preserve the exact behavior. I think moving it to didRecalcStyle makes
sense, though as you said change is modified in between, so I'd prefer to file a
bug and trying to land that change separately.

[rune, 2017/02/06 22:40:44]

I cannot make sense of this at all. layoutObject() seems to always be null for
optgroup inside a select element. If I have an optgroup which does not have a
select parent, I can make it generate a layout object, but then the
ownerSelectElement() will be null. Are you able to come up with a case where
updateListOnLayoutObject() is called below?

[emilio, 2017/02/08 10:59:24]

So I experimented with this, and this condition is completely unreachable as you
said, so I got rid of the custom style callbacks entirely for optgroup too.

     if (HTMLSelectElement* select = ownerSelectElement())
       select->updateListOnLayoutObject();
   }
 }
 
-ComputedStyle* HTMLOptGroupElement::nonLayoutObjectComputedStyle() const {
-  return m_style.get();
-}
-
-PassRefPtr<ComputedStyle> HTMLOptGroupElement::customStyleForLayoutObject() {
-  updateNonComputedStyle();
-  return m_style;
-}
-
 String HTMLOptGroupElement::groupLabelText() const {
   String itemText = getAttribute(labelAttr);
 
   // In WinIE, leading and trailing whitespace is ignored in options and
   // optgroups. We match this behavior.
   itemText = itemText.stripWhiteSpace();
   // We want to collapse our whitespace too.  This will match other browsers.
   itemText = itemText.simplifyWhiteSpace();
 
   return itemText;
@@ skipping 39 matching lines @@
   label.setTextContent(labelText);
   label.setAttribute(aria_labelAttr, AtomicString(labelText));
 }
 
 HTMLDivElement& HTMLOptGroupElement::optGroupLabelElement() const {
   return *toHTMLDivElementOrDie(userAgentShadowRoot()->getElementById(
       ShadowElementNames::optGroupLabel()));
 }
 
 }  // namespace blink