Print Preview: Make print preview tab modal.

chrome/browser/printing/print_preview_tab_controller.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.
 
 // For print preview, a print preview (PP) tab is linked with the initiator tab
 // that initiated the printing operation. If the tab initiates a second
 // printing operation while the first print preview tab is still open, that PP
 // tab is focused/activated. There may be more than one PP tab open. There is a
 // 1:1 relationship between PP tabs and initiating tabs. This class manages PP
 // tabs and initiator tabs.
@@ skipping 86 matching lines @@
   TabContentsWrapper* CreatePrintPreviewTab(TabContentsWrapper* initiator_tab);
 
   // Helper function to store the initiator tab(title and url) information
   // in PrintPreviewUI.
   void SetInitiatorTabURLAndTitle(TabContentsWrapper* preview_tab);
 
   // Adds/Removes observers for notifications from |tab|.
   void AddObservers(TabContentsWrapper* tab);
   void RemoveObservers(TabContentsWrapper* tab);
 
+  // Removes tabs when they close/crash/navigate.
+  void RemoveInitiatorTab(TabContentsWrapper* initiator_tab);
+  void RemovePreviewTab(TabContentsWrapper* preview_tab);
+
   // Mapping between print preview tab and the corresponding initiator tab.
   PrintPreviewTabMap preview_tab_map_;
 
   // A registrar for listening notifications.
   NotificationRegistrar registrar_;
 
   // True if the controller is waiting for a new preview tab via
   // NavigationType::NEW_PAGE.
   bool waiting_for_new_preview_page_;
 
   DISALLOW_COPY_AND_ASSIGN(PrintPreviewTabController);
 };
 
 }  // namespace printing
 
 #endif  // CHROME_BROWSER_PRINTING_PRINT_PREVIEW_TAB_CONTROLLER_H_