[Refactor] Introduce MediaDelegate

ash/new_window_delegate.h

 // Copyright 2013 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 ASH_NEW_WINDOW_DELEGATE_H_
 #define ASH_NEW_WINDOW_DELEGATE_H_
 
 namespace ash {
 
 // A delegate class to create or open windows that are not a part of
 // ash.
 class NewWindowDelegate {
  public:
-  NewWindowDelegate() {}
   virtual ~NewWindowDelegate() {}
 
   // Invoked when the user uses Ctrl+T to open a new tab.
   virtual void NewTab() = 0;
 
   // Invoked when the user uses Ctrl-N or Ctrl-Shift-N to open a new window.
   virtual void NewWindow(bool incognito) = 0;
 
   // Invoked when an accelerator is used to open the file manager.
   virtual void OpenFileManager() = 0;
@@ skipping 10 matching lines @@
   // Shows the task manager window.
   virtual void ShowTaskManager() = 0;
 
   // Opens the feedback page for "Report Issue".
   virtual void OpenFeedbackPage() = 0;
 };
 
 }  // namespace ash
 
 #endif  // ASH_NEW_WINDOW_DELEGATE_H_