Moves ShellObserver to ash/common

ash/system/toast/toast_manager.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_SYSTEM_TOAST_TOAST_MANAGER_H_
 #define ASH_SYSTEM_TOAST_TOAST_MANAGER_H_
 
 #include <deque>
 #include <memory>
 #include <string>
 
 #include "ash/ash_export.h"
-#include "ash/shell_observer.h"
+#include "ash/common/shell_observer.h"
 #include "ash/system/toast/toast_data.h"
 #include "ash/system/toast/toast_overlay.h"
 #include "base/memory/weak_ptr.h"
 #include "base/threading/thread_checker.h"
 
 namespace ash {
 
 // Class managing toast requests.
 class ASH_EXPORT ToastManager : public ToastOverlay::Delegate {
  public:
@@ skipping 27 matching lines @@
   std::unique_ptr<ToastOverlay> overlay_;
 
   base::WeakPtrFactory<ToastManager> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ToastManager);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SYSTEM_TOAST_TOAST_MANAGER_H_