ash: Rename LauncherIconObserver to ShelfIconObserver.

ash/shelf/shelf_icon_observer.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 ASH_SHELF_SHELF_ICON_OBSERVER_H_
+#define ASH_SHELF_SHELF_ICON_OBSERVER_H_
+
+#include "ash/ash_export.h"
+
+namespace ash {
+
+class ASH_EXPORT ShelfIconObserver {
+ public:
+  // Invoked when any icon on shelf changes position.
+  virtual void OnShelfIconPositionsChanged() = 0;
+
+ protected:
+  virtual ~ShelfIconObserver() {}
+};
+
+}  // namespace ash
+
+#endif  // ASH_SHELF_SHELF_ICON_OBSERVER_H_