Remove bad CallJavascriptFunctionUnsafe call from PrintPreviewUI

chrome/browser/printing/background_printing_manager.h

 // Copyright (c) 2012 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_PRINTING_BACKGROUND_PRINTING_MANAGER_H_
 #define CHROME_BROWSER_PRINTING_BACKGROUND_PRINTING_MANAGER_H_
 
 #include <map>
 #include <memory>
 #include <set>
@@ skipping 30 matching lines @@
   // Returns true if |printing_contents_map_| contains |preview_dialog|.
   bool HasPrintPreviewDialog(content::WebContents* preview_dialog);
 
   // Let others see the list of background printing contents.
   std::set<content::WebContents*> CurrentContentSet();
 
   // Delete all preview contents that are associated with |browser_context|.
   void DeletePreviewContentsForBrowserContext(
       content::BrowserContext* browser_context);
 
+  void OnPrintRequestCancelled(content::WebContents* preview_dialog);
+
  private:
   // content::NotificationObserver overrides:
   void Observe(int type,
                const content::NotificationSource& source,
                const content::NotificationDetails& details) override;
 
   // Schedule deletion of |preview_contents|.
   void DeletePreviewContents(content::WebContents* preview_contents);
 
   // A map from print preview WebContentses (managed by
   // BackgroundPrintingManager) to the Observers that observe them.
   std::map<content::WebContents*, std::unique_ptr<Observer>>
       printing_contents_map_;
 
   content::NotificationRegistrar registrar_;
 
   SEQUENCE_CHECKER(sequence_checker_);
 
   DISALLOW_COPY_AND_ASSIGN(BackgroundPrintingManager);
 };
 
 }  // namespace printing
 
 #endif  // CHROME_BROWSER_PRINTING_BACKGROUND_PRINTING_MANAGER_H_