Attempt 2 at fixing crash in ProcessPendingTabs. This differs from the

chrome/browser/ui/browser.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_UI_BROWSER_H_
 #define CHROME_BROWSER_UI_BROWSER_H_
 #pragma once
 
 #include <map>
 #include <set>
@@ skipping 891 matching lines @@
   void CancelWindowClose();
 
   // Removes |tab| from the passed |set|.
   // Returns whether the tab was in the set in the first place.
   // TODO(beng): this method needs a better name!
   bool RemoveFromSet(UnloadListenerSet* set, TabContents* tab);
 
   // Cleans up state appropriately when we are trying to close the browser and
   // the tab has finished firing its unload handler. We also use this in the
   // cases where a tab crashes or hangs even if the beforeunload/unload haven't
-  // successfully fired.
-  void ClearUnloadState(TabContents* tab);
+  // successfully fired. If |process_now| is true |ProcessPendingTabs| is
+  // invoked immediately, otherwise it is invoked after a delay (PostTask).
+  //
+  // Typically you'll want to pass in true for |process_now|. Passing in true
+  // may result in deleting |tab|. If you know that shouldn't happen (because of
+  // the state of the stack), pass in false.
+  void ClearUnloadState(TabContents* tab, bool process_now);
 
   // In-progress download termination handling /////////////////////////////////
 
   // Called when the window is closing to check if potential in-progress
   // downloads should prevent it from closing.
   // Returns true if the window can close, false otherwise.
   bool CanCloseWithInProgressDownloads();
 
   // Assorted utility functions ///////////////////////////////////////////////
 
@@ skipping 207 matching lines @@
   // and we install ourselves as an observer.
   TabRestoreService* tab_restore_service_;
 
   scoped_ptr<InstantController> instant_;
   scoped_ptr<InstantUnloadHandler> instant_unload_handler_;
 
   DISALLOW_COPY_AND_ASSIGN(Browser);
 };
 
 #endif  // CHROME_BROWSER_UI_BROWSER_H_