chromeos webui: remove DialogDelegate GetDialogButtons override

The override just restated the default, so take it out altogether.

Bug: 1011446
Change-Id: Iee89b0619d9e3c50f43e4c8ab6437d0f31a7f138
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2015666Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Commit-Queue: Elly Fong-Jones <ellyjones@chromium.org>
Cr-Commit-Position: refs/heads/master@{#735544}

chrome/browser/ui/webui/chromeos/add_supervision/confirm_signout_dialog.cc

@@ -69,11 +69,6 @@ bool ConfirmSignoutDialog::Accept() {
   return true;
 }
 
-int ConfirmSignoutDialog::GetDialogButtons() const {
-  return ui::DialogButton::DIALOG_BUTTON_OK |
-         ui::DialogButton::DIALOG_BUTTON_CANCEL;
-}
-
 // static
 views::Widget* ConfirmSignoutDialog::current_instance_ = nullptr;
 

chrome/browser/ui/webui/chromeos/add_supervision/confirm_signout_dialog.h

@@ -28,7 +28,6 @@ class ConfirmSignoutDialog : public views::DialogDelegateView {
 
   // views::DialogDelegate:
   bool Accept() override;
-  int GetDialogButtons() const override;
 
   static void Show();
   static bool IsShowing();