Fix handling of tab contents disappearing out from underneath Javascript dialogs.

chrome/browser/ui/app_modal_dialogs/app_modal_dialog_queue.h

 // Copyright (c) 2011 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_APP_MODAL_DIALOGS_APP_MODAL_DIALOG_QUEUE_H_
 #define CHROME_BROWSER_UI_APP_MODAL_DIALOGS_APP_MODAL_DIALOG_QUEUE_H_
 #pragma once
 
 #include <deque>
 
 #include "chrome/browser/ui/app_modal_dialogs/app_modal_dialog.h"
 
 template <typename T> struct DefaultSingletonTraits;
 
 // Keeps a queue of AppModalDialogs, making sure only one app modal
 // dialog is shown at a time.
 // This class is a singleton.
 class AppModalDialogQueue {
  public:
   // Returns the singleton instance.
   static AppModalDialogQueue* GetInstance();
 
-  // Adds a modal dialog to the queue, if there are no other dialogs in the
+  // Adds a modal dialog to the queue. If there are no other dialogs in the
   // queue, the dialog will be shown immediately. Once it is shown, the
   // most recently active browser window (or whichever is currently active)
   // will be app modal, meaning it will be activated if the user tries to
   // activate any other browser windows. So the dialog being shown should
   // assure it is the child of BrowserList::GetLastActive() so that it is
   // activated as well. See browser_list.h for more notes about our somewhat
   // sloppy app modality.
   // Note: The AppModalDialog |dialog| must be window modal before it
   // can be added as app modal.
   void AddDialog(AppModalDialog* dialog);
@@ skipping 15 matching lines @@
   // Returns true if there is currently an active app modal dialog box.
   bool HasActiveDialog() {
     return active_dialog_ != NULL;
   }
 
   // Accessor for |active_dialog_|.
   AppModalDialog* active_dialog() {
     return active_dialog_;
   }
 
-  // Iterators to walk the queue.
+  // Iterators to walk the queue. The queue does not include the currently
+  // active app modal dialog box.
   typedef std::deque<AppModalDialog*>::iterator iterator;
   iterator begin() {
     return app_modal_dialog_queue_.begin();
   }
 
   iterator end() {
     return app_modal_dialog_queue_.end();
   }
 
  private:
   friend struct DefaultSingletonTraits<AppModalDialogQueue>;
 
   AppModalDialogQueue();
   ~AppModalDialogQueue();
 
   // Shows |dialog| and notifies the BrowserList that a modal dialog is showing.
   void ShowModalDialog(AppModalDialog* dialog);
 
   // Returns the next dialog to show. This removes entries from
   // app_modal_dialog_queue_ until one is valid or the queue is empty. This
   // returns NULL if there are no more dialogs, or all the dialogs in the queue
   // are not valid.
   AppModalDialog* GetNextDialog();
 
-  // Contains all app modal dialogs which are waiting to be shown, with the
-  // currently modal dialog at the front of the queue.
+  // Contains all app modal dialogs which are waiting to be shown. The currently
+  // active modal dialog is not included.
   std::deque<AppModalDialog*> app_modal_dialog_queue_;
 
   // The currently active app-modal dialog box's delegate. NULL if there is no
   // active app-modal dialog box.
   AppModalDialog* active_dialog_;
 
   // Stores if |ShowModalDialog()| is currently being called on an app-modal
   // dialog.
   bool showing_modal_dialog_;
 
   DISALLOW_COPY_AND_ASSIGN(AppModalDialogQueue);
 };
 
 #endif  // CHROME_BROWSER_UI_APP_MODAL_DIALOGS_APP_MODAL_DIALOG_QUEUE_H_