Revert of Simplify form validation handling

Source/core/html/HTMLFormElement.h

Index: Source/core/html/HTMLFormElement.h
diff --git a/Source/core/html/HTMLFormElement.h b/Source/core/html/HTMLFormElement.h
index 0bbd9cd347e38928dc6dab7ed278ea498db938fa..8b46c5cade6fcb4356be88c569b88d171c0b268e 100644
--- a/Source/core/html/HTMLFormElement.h
+++ b/Source/core/html/HTMLFormElement.h
@@ -47,6 +47,8 @@
     static PassRefPtrWillBeRawPtr<HTMLFormElement> create(Document&);
     virtual ~HTMLFormElement();
     DECLARE_VIRTUAL_TRACE();
+
+    void setNeedsValidityCheck(ValidityRecalcReason, bool isValid);
 
     PassRefPtrWillBeRawPtr<HTMLFormControlsCollection> elements();
     void getNamedElements(const AtomicString&, WillBeHeapVector<RefPtrWillBeMember<Element>>&);
@@ -184,6 +186,10 @@
 
     bool m_wasDemoted : 1;
 
+    // Number of invalid elements associated to the form that are candidates
+    // for constraint validation (their willValidate state is true).
+    int m_invalidControlsCount;
+
     OwnPtrWillBeMember<GenericEventQueue> m_pendingAutocompleteEventsQueue;
 };