Makes instant run before unload listeners.

chrome/browser/tab_contents/tab_contents_delegate.h

 // Copyright (c) 2010 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_TAB_CONTENTS_TAB_CONTENTS_DELEGATE_H_
 #define CHROME_BROWSER_TAB_CONTENTS_TAB_CONTENTS_DELEGATE_H_
 #pragma once
 
 #include <string>
 #include <vector>
@@ skipping 140 matching lines @@
   // Reloading can be disabled e. g. for the DevTools window.
   virtual bool CanReloadContents(TabContents* source) const;
 
   // Show a dialog with HTML content. |delegate| contains a pointer to the
   // delegate who knows how to display the dialog (which file URL and JSON
   // string input to use during initialization). |parent_window| is the window
   // that should be parent of the dialog, or NULL for the default.
   virtual void ShowHtmlDialog(HtmlDialogUIDelegate* delegate,
                               gfx::NativeWindow parent_window);
 
+  // Invoked prior to showing before unload handler confirmation dialog.
+  virtual void WillRunBeforeUnloadConfirm();
+
   // Returns true if javascript dialogs and unload alerts are suppressed.
   // Default is false.
   virtual bool ShouldSuppressDialogs();
 
   // Tells us that we've finished firing this tab's beforeunload event.
   // The proceed bool tells us whether the user chose to proceed closing the
   // tab. Returns true if the tab can continue on firing it's unload event.
   // If we're closing the entire browser, then we'll want to delay firing
   // unload events until all the beforeunload events have fired.
   virtual void BeforeUnloadFired(TabContents* tab,
@@ skipping 145 matching lines @@
 
   // Notifies the delegate that the content restrictions for this tab has
   // changed.
   virtual void ContentRestrictionsChanged(TabContents* source);
 
  protected:
   virtual ~TabContentsDelegate();
 };
 
 #endif  // CHROME_BROWSER_TAB_CONTENTS_TAB_CONTENTS_DELEGATE_H_