Bug 1966349 - Make sure NavigateEvent is initialized correctly. r=jjaschke

Make sure the  properties downloadRequest and userInitiated get their
correct values.

Differential Revision: https://phabricator.services.mozilla.com/D249243

docshell/base/nsDocShell.cpp

@@ -12979,6 +12979,7 @@ nsresult nsDocShell::OnLinkClick(
   loadState->SetTextDirectiveUserActivation(
       ownerDoc->ConsumeTextDirectiveUserActivation() ||
       hasValidUserGestureActivation);
+  loadState->SetUserNavigationInvolvement(aUserInvolvement);
 
   nsCOMPtr<nsIRunnable> ev = new OnLinkClickEvent(
       this, aContent, loadState, noOpenerImplied, aTriggeringPrincipal);

dom/navigation/Navigation.cpp

@@ -526,7 +526,7 @@ bool Navigation::FireTraverseNavigateEvent(
       /* aSourceElement */ nullptr,
       /* aFormDataEntryList*/ Nothing(),
       /* aClassicHistoryAPIState */ nullptr,
-      /* aDownloadRequestFilename */ u""_ns);
+      /* aDownloadRequestFilename */ VoidString());
 }
 
 // https://html.spec.whatwg.org/#fire-a-push/replace/reload-navigate-event
@@ -552,7 +552,7 @@ bool Navigation::FirePushReplaceReloadNavigateEvent(
       aCx, aNavigationType, destination,
       aUserInvolvement.valueOr(UserNavigationInvolvement::None), aSourceElement,
       aFormDataEntryList, aClassicHistoryAPIState,
-      /* aDownloadRequestFilename */ u""_ns);
+      /* aDownloadRequestFilename */ VoidString());
 }
 
 // https://html.spec.whatwg.org/#fire-a-download-request-navigate-event