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 666919516288a88e6f76a536bdc695e1b6d262d6..6ab1479222e72940eeb9ed24cb78fbfd64b4288b 100644
--- a/third_party/WebKit/Source/core/html/HTMLOptGroupElement.cpp
+++ b/third_party/WebKit/Source/core/html/HTMLOptGroupElement.cpp
@@ -75,19 +75,6 @@ void HTMLOptGroupElement::parseAttribute(
   }
 }
 
-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())
@@ -117,23 +104,13 @@ void HTMLOptGroupElement::removedFrom(ContainerNode* insertionPoint) {
   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);