After signin token check failed, show force reauth dialog and start window closing countdown.

chrome/browser/ui/forced_reauthentication_dialog_delegate.h

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_UI_FORCED_REAUTHENTICATION_DIALOG_DELEGATE_H_
+#define CHROME_BROWSER_UI_FORCED_REAUTHENTICATION_DIALOG_DELEGATE_H_
+
+#include "base/macros.h"
+#include "base/memory/weak_ptr.h"
+
+class ForcedReauthenticationDialog;
+class Profile;
+class SigninManager;
+
+namespace base {
+class TimeDelta;
+}  // namespace base
+
+// A helper class to show/hide ForcedReauthenticationDialog.
+class ForcedReauthenticationDialogDelegate {

[sky, 2017/06/23 17:06:04]

Much better, thanks.
It isn't clear why this has Delegate in the name. There is no delegation here.
How about ForcedReauthenticationDialog as that is what this is, right? You can
name the views one ForcedReauthenticationDialogViews.
Also, make this pure virtual with a create function. That way you don't need the
dialog_ member as it's handled by the appropriate implementation.

+ public:
+  ForcedReauthenticationDialogDelegate();
+  ~ForcedReauthenticationDialogDelegate();
+  // Show the ForcedReauthenticationDialog for |profile|. If there're no opened
+  // browser windows for |profile|, |signin_manager| will be called to signed
+  // out immediately. Otherwise, dialog will be closed with all browser windows
+  // are assoicated to |profile| after |countdown_duration| if there is no
+  // reauth.
+  void ShowDialog(Profile* profile,
+                  SigninManager* signin_manager,
+                  base::TimeDelta countdown_duration);
+
+  void CloseDialog();

[sky, 2017/06/23 17:06:04]

Is there a reason for the explicit close? AFAICT this is only called from the
destructor, so that if you make the destructor implicitly close the dialog you
don't need this.

+
+ private:
+  base::WeakPtr<ForcedReauthenticationDialog> dialog_;
+
+  DISALLOW_COPY_AND_ASSIGN(ForcedReauthenticationDialogDelegate);
+};
+
+#endif  // CHROME_BROWSER_UI_FORCED_REAUTHENTICATION_DIALOG_DELEGATE_H_