Bug 1615498 - [1.0] Remove all window event listener before disconnecting the manager. r=smaug

Differential Revision: https://phabricator.services.mozilla.com/D64439

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

dom/base/nsGlobalWindowInner.cpp

@@ -1080,6 +1080,7 @@ void nsGlobalWindowInner::FreeInnerObjects() {
   mChromeEventHandler = nullptr;
 
   if (mListenerManager) {
+    mListenerManager->RemoveAllListeners();
     mListenerManager->Disconnect();
     mListenerManager = nullptr;
   }