Bug 1528644 - Internal value changes shouldn't change validity state. r=masayuki

Even less so on reframe, where it's just unsound to do so. I had to give a value
to eSetValue_Internal, since otherwise I cannot check for its presence. I can
further special-case the reframe case if you prefer.

Differential Revision: https://phabricator.services.mozilla.com/D20133

dom/html/HTMLTextAreaElement.cpp

@@ -1111,9 +1111,10 @@ HTMLTextAreaElement::InitializeKeyboardEventListeners() {
 }
 
 NS_IMETHODIMP_(void)
-HTMLTextAreaElement::OnValueChanged(bool aNotify,
-                                    bool aWasInteractiveUserChange) {
-  mLastValueChangeWasInteractive = aWasInteractiveUserChange;
+HTMLTextAreaElement::OnValueChanged(bool aNotify, ValueChangeKind aKind) {
+  if (aKind != ValueChangeKind::Internal) {
+    mLastValueChangeWasInteractive = aKind == ValueChangeKind::UserInteraction;
+  }
 
   // Update the validity state
   bool validBefore = IsValid();