Nicely handle OnBeforeUnloads with guest and lock mode.

chrome/browser/ui/unload_controller.cc

Index: chrome/browser/ui/unload_controller.cc
diff --git a/chrome/browser/ui/unload_controller.cc b/chrome/browser/ui/unload_controller.cc
index fab4eb76d245679c9559e4763ceeb6c1f03b3ca6..e0cc70e6291d8be530d13927643dfebec62429cf 100644
--- a/chrome/browser/ui/unload_controller.cc
+++ b/chrome/browser/ui/unload_controller.cc
@@ -300,7 +300,10 @@ void UnloadController::ProcessPendingTabs() {
       ClearUnloadState(web_contents, true);
     }
   } else if (is_calling_before_unload_handlers()) {
-    on_close_confirmed_.Run(true);
+    base::Callback<void(bool)> on_close_confirmed = on_close_confirmed_;
+    if (tabs_needing_unload_fired_.empty())
+      on_close_confirmed_.Reset();

[Peter Kasting, 2014/08/28 18:46:13]

Clearly order is important here; add comments explaining the control flow and
why we need to reset the member before running the callback.

[Mike Lerman, 2014/08/29 18:02:21]

Done.

+    on_close_confirmed.Run(true);
   } else if (!tabs_needing_unload_fired_.empty()) {
     // We've finished firing all beforeunload events and can proceed with unload
     // events.