Eliminate mojo::Shell client lib class

ash/mus/keyboard_ui_mus.h

 // Copyright 2016 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_MUS_KEYBOARD_UI_MUS_H_
 #define ASH_MUS_KEYBOARD_UI_MUS_H_
 
 #include "ash/keyboard/keyboard_ui.h"
 #include "base/macros.h"
 #include "mojo/public/cpp/bindings/binding.h"
 #include "ui/keyboard/keyboard.mojom.h"
 
 namespace mojo {
-class Shell;
+class Connector;
 }
 
 namespace ash {
 
 class KeyboardUIMus : public KeyboardUI,
                       public keyboard::mojom::KeyboardObserver {
  public:
-  explicit KeyboardUIMus(mojo::Shell* mojo_shell);
+  explicit KeyboardUIMus(mojo::Connector* connector);
   ~KeyboardUIMus() override;
 
-  static scoped_ptr<KeyboardUI> Create(mojo::Shell* mojo_shell);
+  static scoped_ptr<KeyboardUI> Create(mojo::Connector* connector);
 
   // KeyboardUI:
   void Hide() override;
   void Show() override;
   bool IsEnabled() override;
 
   // keyboard::mojom::KeyboardObserver:
   void OnKeyboardStateChanged(bool is_enabled,
                               bool is_visible,
                               uint64_t display_id,
                               mojo::RectPtr bounds) override;
 
  private:
   bool is_enabled_;
 
   keyboard::mojom::KeyboardPtr keyboard_;
   mojo::Binding<keyboard::mojom::KeyboardObserver> observer_binding_;
 
   DISALLOW_COPY_AND_ASSIGN(KeyboardUIMus);
 };
 
 }  // namespace ash
 
 #endif  // ASH_MUS_KEYBOARD_UI_MUS_H_