Bug 1712255 - Defer SetMaxLength in SetValueFromSetRangeText r=masayuki

Capping selection range in SetValue early makes the subsequent SetSelectionRange call unable to detect actual selection range change. This patch defers it so that select events can be consistently fired.

Differential Revision: https://phabricator.services.mozilla.com/D115729

dom/html/HTMLTextAreaElement.cpp

@@ -660,6 +660,7 @@ void HTMLTextAreaElement::GetValueFromSetRangeText(nsAString& aValue) {
 nsresult HTMLTextAreaElement::SetValueFromSetRangeText(
     const nsAString& aValue) {
   return SetValueInternal(aValue, {ValueSetterOption::ByContentAPI,
+                                   ValueSetterOption::BySetRangeTextAPI,
                                    ValueSetterOption::SetValueChanged});
 }