Bug 1262110 - Null out nsIMacDockSupport.dockMenu on shutdown. r=smaug.

--HG--
extra : rebase_source : 230f640b44d8ecbb846780584c608827d012680c

browser/base/content/browser.js

@@ -1573,6 +1573,10 @@ if (AppConstants.platform == "macosx") {
   };
 
   gBrowserInit.nonBrowserWindowShutdown = function() {
+    let dockSupport = Cc["@mozilla.org/widget/macdocksupport;1"]
+                      .getService(Ci.nsIMacDockSupport);
+    dockSupport.dockMenu = null;
+
     // If nonBrowserWindowDelayedStartup hasn't run yet, we have no work to do -
     // just cancel the pending timeout and return;
     if (this._delayedStartupTimeoutId) {

widget/cocoa/nsMacDockSupport.mm

@@ -39,20 +39,16 @@ nsMacDockSupport::~nsMacDockSupport()
 NS_IMETHODIMP
 nsMacDockSupport::GetDockMenu(nsIStandaloneNativeMenu ** aDockMenu)
 {
-  *aDockMenu = nullptr;
-
-  if (mDockMenu)
-    return mDockMenu->QueryInterface(NS_GET_IID(nsIStandaloneNativeMenu),
-                                     reinterpret_cast<void **>(aDockMenu));
+  nsCOMPtr<nsIStandaloneNativeMenu> dockMenu(mDockMenu);
+  dockMenu.forget(aDockMenu);
   return NS_OK;
 }
 
 NS_IMETHODIMP
 nsMacDockSupport::SetDockMenu(nsIStandaloneNativeMenu * aDockMenu)
 {
-  nsresult rv;
-  mDockMenu = do_QueryInterface(aDockMenu, &rv);
-  return rv;
+  mDockMenu = aDockMenu;
+  return NS_OK;
 }
 
 NS_IMETHODIMP