Bug 1656980 - CookieService::GetCookiesSince needs to check the CookieService initialization state, r=mayhemer

Differential Revision: https://phabricator.services.mozilla.com/D85824

netwerk/cookie/CookieService.cpp

@@ -2237,6 +2237,10 @@ class CompareCookiesCreationTime {
 NS_IMETHODIMP
 CookieService::GetCookiesSince(int64_t aSinceWhen,
                                nsTArray<RefPtr<nsICookie>>& aResult) {
+  if (!IsInitialized()) {
+    return NS_OK;
+  }
+
   mPersistentStorage->EnsureReadComplete();
 
   // We expose only non-private cookies.