Turned UiStrings into a singleton so that the continue window does not depend on ChromotingHost.

remoting/host/continue_window.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 REMOTING_HOST_CONTINUE_WINDOW_H_
 #define REMOTING_HOST_CONTINUE_WINDOW_H_
 
 #include "base/callback.h"
 
 namespace remoting {
 
-class ChromotingHost;
+struct UiStrings;
 
 class ContinueWindow {
  public:
   // ContinueSessionCallback is called when the user clicks on the
   // Continue button to resume the session, or dismisses the window to
   // terminate the session.  This callback is provided as a parameter to the
   // Show() method, and will be triggered on the UI thread.
   typedef base::Callback<void(bool)> ContinueSessionCallback;
 
   virtual ~ContinueWindow() {}
 
   // Show the continuation window requesting that the user approve continuing
   // the session.
-  virtual void Show(ChromotingHost* host,
-                    const ContinueSessionCallback& callback) = 0;
+  virtual void Show(const ContinueSessionCallback& callback) = 0;
 
   // Hide the continuation window if it is visible.
   virtual void Hide() = 0;
 
-  static scoped_ptr<ContinueWindow> Create();
+  static scoped_ptr<ContinueWindow> Create(const UiStrings* ui_strings);
 };
 
 }  // namespace remoting
 
 #endif  // REMOTING_HOST_CONTINUE_WINDOW_H_