Implement :valid and :invalid pseudoclass for <form>

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 6029f3fe1e814339a8d896db5eb0e1bf69de265b..ebc2ecddc4c74bafd565b1ab24af3c29265c8ea2 100644
--- a/Source/core/html/HTMLFormControlElement.cpp
+++ b/Source/core/html/HTMLFormControlElement.cpp
@@ -469,7 +469,7 @@ ValidationMessageClient* HTMLFormControlElement::validationMessageClient() const
 
 bool HTMLFormControlElement::checkValidity(WillBeHeapVector<RefPtrWillBeMember<FormAssociatedElement> >* unhandledInvalidControls)
 {
-    if (!willValidate() || isValidFormControlElement())
+    if (!willValidate() || isValidElement())
         return true;
     // An event handler can deref this object.
     RefPtrWillBeRawPtr<HTMLFormControlElement> protector(this);
@@ -480,7 +480,7 @@ bool HTMLFormControlElement::checkValidity(WillBeHeapVector<RefPtrWillBeMember<F
     return false;
 }
 
-bool HTMLFormControlElement::isValidFormControlElement()
+bool HTMLFormControlElement::isValidElement()
 {
     // If the following assertion fails, setNeedsValidityCheck() is not called
     // correctly when something which changes validity is updated.
@@ -493,6 +493,13 @@ void HTMLFormControlElement::setNeedsValidityCheck()
     bool newIsValid = valid();
     if (willValidate() && newIsValid != m_isValid) {
         // Update style for pseudo classes such as :valid :invalid.
+        // A change here could've affected the style of the form itself and
+        // other form elemetns, so recaluclate the entire form's subtree.

[keishi, 2014/10/01 09:25:27]

nit: /elemetns/elements/
nit: /recaluclate/recalculate/

[Bartek Nowierski, 2014/10/02 14:26:42]

Done.

+        HTMLFormElement* form = formOwner();
+        if (form)
+            form->setNeedsStyleRecalc(SubtreeStyleChange, StyleChangeReasonForTracing::createWithExtraData(StyleChangeReason::PseudoClass, StyleChangeExtraData::Invalid));
+        // Then recalculate the element itself (and its subtree), because
+        // it might not be in the tree of the owner form.
         setNeedsStyleRecalc(SubtreeStyleChange, StyleChangeReasonForTracing::createWithExtraData(StyleChangeReason::PseudoClass, StyleChangeExtraData::Invalid));
     }
     m_isValid = newIsValid;