Bug 1556364 - Part 2-1: Split nsGenericHTMLFormControlElement-only members from nsIConstraintValidation to a separated class; r=smaug

As ElementInternal has it own implmentation.

Differential Revision: https://phabricator.services.mozilla.com/D130259

dom/html/HTMLTextAreaElement.cpp

@@ -928,7 +928,7 @@ bool HTMLTextAreaElement::IsValueEmpty() const {
 }
 
 void HTMLTextAreaElement::SetCustomValidity(const nsAString& aError) {
-  nsIConstraintValidation::SetCustomValidity(aError);
+  ConstraintValidation::SetCustomValidity(aError);
 
   UpdateState(true);
 }
@@ -1039,8 +1039,8 @@ nsresult HTMLTextAreaElement::GetValidationMessage(
       aValidationMessage = message;
     } break;
     default:
-      rv = nsIConstraintValidation::GetValidationMessage(aValidationMessage,
-                                                         aType);
+      rv =
+          ConstraintValidation::GetValidationMessage(aValidationMessage, aType);
   }
 
   return rv;