Bug 1864291 - Implements HandleInvokeInternal for select and input elements. r=smaug

Implements invoketarget defaults for select and input element, as specified in the open-ui "Invokers explainer".

(https://open-ui.org/components/invokers.explainer/)

Differential Revision: https://phabricator.services.mozilla.com/D193363

dom/html/HTMLInputElement.cpp

@@ -5755,10 +5755,22 @@ void HTMLInputElement::ShowPicker(ErrorResult& aRv) {
   //
   // https://html.spec.whatwg.org/multipage/input.html#show-the-picker,-if-applicable
   // To show the picker, if applicable for an input element element:
+  ShowThePickerIfApplicable();
+}
+
+void HTMLInputElement::ShowThePickerIfApplicable() {
+  // https://html.spec.whatwg.org/multipage/input.html#show-the-picker,-if-applicable
+  // To show the picker, if applicable for an input element element:
 
   // Step 1. Assert: element's relevant global object has transient activation.
+  if (!OwnerDoc()->HasValidTransientUserGestureActivation()) {
+    return;
+  }
+
   // Step 2. If element is not mutable, then return.
-  // (See above.)
+  if (!IsMutable()) {
+    return;
+  }
 
   // Step 3. If element's type attribute is in the File Upload state, then run
   // these steps in parallel:
@@ -7324,6 +7336,23 @@ void HTMLInputElement::MaybeFireInputPasswordRemoved() {
       ChromeOnlyDispatch::eYes);
 }
 
+void HTMLInputElement::HandleInvokeInternal(nsAtom* aAction, ErrorResult& aRv) {
+  // If this's relevant settings object's origin is not same origin with
+  // this's relevant settings object's top-level origin, [...], then return.
+  nsPIDOMWindowInner* window = OwnerDoc()->GetInnerWindow();
+  WindowGlobalChild* windowGlobalChild =
+      window ? window->GetWindowGlobalChild() : nullptr;
+  if (!windowGlobalChild || !windowGlobalChild->SameOriginWithTop()) {
+    return;
+  }
+
+  // If action is an ASCII case-insensitive match for "showPicker"
+  // then show the picker, if applicable for this.
+  if (nsContentUtils::EqualsIgnoreASCIICase(aAction, nsGkAtoms::showPicker)) {
+    ShowThePickerIfApplicable();
+  }
+}
+
 }  // namespace mozilla::dom
 
 #undef NS_ORIGINAL_CHECKED_VALUE