Implement :valid and :invalid pseudoclass for <fieldset>

Source/core/html/HTMLFormControlElement.cpp

Index: Source/core/html/HTMLFormControlElement.cpp
diff --git a/Source/core/html/HTMLFormControlElement.cpp b/Source/core/html/HTMLFormControlElement.cpp
index d0b933ef8e7678445183ffcec72a861ebe09657c..a2836e266ee9e328509971e77e6789f997a31834 100644
--- a/Source/core/html/HTMLFormControlElement.cpp
+++ b/Source/core/html/HTMLFormControlElement.cpp
@@ -253,11 +253,13 @@ Node::InsertionNotificationRequest HTMLFormControlElement::insertedInto(Containe
     setNeedsWillValidateCheck();
     HTMLElement::insertedInto(insertionPoint);
     FormAssociatedElement::insertedInto(insertionPoint);
+    fieldSetAncestorsSetNeedsValidityCheck(insertionPoint);
     return InsertionDone;
 }
 
 void HTMLFormControlElement::removedFrom(ContainerNode* insertionPoint)
 {
+    fieldSetAncestorsSetNeedsValidityCheck(insertionPoint);
     hideVisibleValidationMessage();
     m_hasValidationMessage = false;
     m_ancestorDisabledState = AncestorDisabledStateUnknown;
@@ -285,6 +287,20 @@ void HTMLFormControlElement::formOwnerSetNeedsValidityCheck()
         form->setNeedsValidityCheck();
 }
 
+void HTMLFormControlElement::fieldSetAncestorsSetNeedsValidityCheck(Node* node)
+{
+    if (!node)
+        return;
+    HTMLFieldSetElement* fieldSet = Traversal<HTMLFieldSetElement>::firstAncestorOrSelf(*node);
+    HTMLFieldSetElement* lastFieldSet = 0;
+    while (fieldSet) {
+        lastFieldSet = fieldSet;
+        fieldSet = Traversal<HTMLFieldSetElement>::firstAncestor(*fieldSet);
+    }
+    if (lastFieldSet)
+        lastFieldSet->setNeedsValidityCheck();
+}
+
 void HTMLFormControlElement::setChangedSinceLastFormControlChangeEvent(bool changed)
 {
     m_wasChangedSinceLastFormControlChangeEvent = changed;
@@ -519,6 +535,7 @@ void HTMLFormControlElement::setNeedsValidityCheck()
     bool newIsValid = valid();
     if (willValidate() && newIsValid != m_isValid) {
         formOwnerSetNeedsValidityCheck();
+        fieldSetAncestorsSetNeedsValidityCheck(this->parentNode());

[tkent, 2014/10/19 23:56:40]

|this->| is unnecessary.

I'm afraid this causes a performance regression.
Please confirm PerformanceTest/DOM/textarea-*.html won't regress with this
patch.
You can run them with a command like:
  ./third_party/WebKit/Tools/Scripts/run-perf-tests DOM/textarea-edit.html

[Bartek Nowierski, 2014/10/20 10:43:10]

Done.
As discussed on the chat, proceeding as is because this didn't cause a visible
change in perf of DOM/textarea-*.html tests.

         // Update style for pseudo classes such as :valid :invalid.
         setNeedsStyleRecalc(SubtreeStyleChange, StyleChangeReasonForTracing::createWithExtraData(StyleChangeReason::PseudoClass, StyleChangeExtraData::Invalid));
     }