Add ShellDelegate, MediaDelegate and KeyboardUI stubs to mus ash

ash/common/wm_shell.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_COMMON_WM_SHELL_H_
 #define ASH_COMMON_WM_SHELL_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 200 matching lines @@
 #if defined(OS_CHROMEOS)
   LogoutConfirmationController* logout_confirmation_controller() {
     return logout_confirmation_controller_.get();
   }
 
   // TODO(jamescook): Remove this when VirtualKeyboardController has been moved.
   virtual void ToggleIgnoreExternalKeyboard() = 0;
 #endif
 
  protected:
-  explicit WmShell(ShellDelegate* delegate);
+  explicit WmShell(std::unique_ptr<ShellDelegate> shell_delegate);
   virtual ~WmShell();
 
   base::ObserverList<ShellObserver>* shell_observers() {
     return &shell_observers_;
   }
 
   void SetKeyboardUI(std::unique_ptr<KeyboardUI> keyboard_ui);
 
   // Helpers to set (and initialize) or destroy various delegates.
   // TODO(msw|jamescook): Remove these once ShellDelegate, etc. are ported.
@@ skipping 33 matching lines @@
   bool simulate_modal_window_open_for_testing_ = false;
 
 #if defined(OS_CHROMEOS)
   std::unique_ptr<LogoutConfirmationController> logout_confirmation_controller_;
 #endif
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_WM_SHELL_H_