Bug 1509340 - Don't dispatch STATE_COOKIES_LOADED notifications from the parent process for fastblock r=baku

Differential Revision: https://phabricator.services.mozilla.com/D12679

--HG--
extra : moz-landing-system : lando

toolkit/components/antitracking/AntiTrackingCommon.cpp

@@ -1293,7 +1293,7 @@ AntiTrackingCommon::NotifyBlockingDecision(nsIChannel* aChannel,
     // Tell the child process channel to do this instead.
     if (aDecision == BlockingDecision::eBlock) {
       parentChannel->NotifyTrackingCookieBlocked(aRejectedReason);
-    } else {
+    } else if (sendCookieLoadedNotification) {
       // Ignore the code related to fastblock
       parentChannel->NotifyCookieAllowed();
     }