Bug 1680611 - part 11: Mark `nsFocusManager::NotifyOfReFocus()` as `MOZ_CAN_RUN_SCRIPT` r=smaug

Differential Revision: https://phabricator.services.mozilla.com/D147072

dom/base/Element.cpp

@@ -447,10 +447,11 @@ int32_t Element::TabIndex() {
 
 void Element::Focus(const FocusOptions& aOptions, CallerType aCallerType,
                     ErrorResult& aError) {
-  RefPtr<nsFocusManager> fm = nsFocusManager::GetFocusManager();
-  if (!fm) {
+  const RefPtr<nsFocusManager> fm = nsFocusManager::GetFocusManager();
+  if (MOZ_UNLIKELY(!fm)) {
     return;
   }
+  const OwningNonNull<Element> kungFuDeathGrip(*this);
   // Also other browsers seem to have the hack to not re-focus (and flush) when
   // the element is already focused.
   // Until https://github.com/whatwg/html/issues/4512 is clarified, we'll
@@ -458,7 +459,7 @@ void Element::Focus(const FocusOptions& aOptions, CallerType aCallerType,
   // I.e., `focus({ preventScroll: true})` followed by `focus( { preventScroll:
   // false })` won't re-focus.
   if (fm->CanSkipFocus(this)) {
-    fm->NotifyOfReFocus(*this);
+    fm->NotifyOfReFocus(kungFuDeathGrip);
     fm->NeedsFlushBeforeEventHandling(this);
     return;
   }
@@ -466,7 +467,7 @@ void Element::Focus(const FocusOptions& aOptions, CallerType aCallerType,
   if (aCallerType == CallerType::NonSystem) {
     fmFlags |= nsIFocusManager::FLAG_NONSYSTEMCALLER;
   }
-  aError = fm->SetFocus(this, fmFlags);
+  aError = fm->SetFocus(kungFuDeathGrip, fmFlags);
 }
 
 void Element::SetTabIndex(int32_t aTabIndex, mozilla::ErrorResult& aError) {

dom/base/Element.h

@@ -301,6 +301,8 @@ class Element : public FragmentOrElement {
   /**
    * Make focus on this element.
    */
+  // TODO: Convert Focus() to MOZ_CAN_RUN_SCRIPT and get rid of the
+  //       kungFuDeathGrip in it.
   MOZ_CAN_RUN_SCRIPT_BOUNDARY virtual void Focus(const FocusOptions& aOptions,
                                                  const CallerType aCallerType,
                                                  ErrorResult& aError);

dom/base/nsFocusManager.h

@@ -290,7 +290,7 @@ class nsFocusManager final : public nsIFocusManager,
    *
    * aContent is focused content.
    */
-  MOZ_CAN_RUN_SCRIPT_BOUNDARY void NotifyOfReFocus(nsIContent& aContent);
+  MOZ_CAN_RUN_SCRIPT void NotifyOfReFocus(nsIContent& aContent);
 
   static void MarkUncollectableForCCGeneration(uint32_t aGeneration);