Remove DialogDelegate::OnClosed() which is redundant with

chrome/browser/ui/views/first_run_dialog.h

Index: chrome/browser/ui/views/first_run_dialog.h
diff --git a/chrome/browser/ui/views/first_run_dialog.h b/chrome/browser/ui/views/first_run_dialog.h
index 91fe12e456a101308ccf25e92089e4959b608f53..f9e0276fe6594c9c2795eccce1700ffc52370663 100644
--- a/chrome/browser/ui/views/first_run_dialog.h
+++ b/chrome/browser/ui/views/first_run_dialog.h
@@ -33,10 +33,12 @@ class FirstRunDialog : public views::DialogDelegateView,
 
   // views::DialogDelegate:
   views::View* CreateExtraView() override;
-  void OnClosed() override;
   bool Accept() override;
   int GetDialogButtons() const override;
 
+  // views::WidgetDelegate:
+  void WindowClosing() override;
+
   // views::LinkListener:
   void LinkClicked(views::Link* source, int event_flags) override;