Removes WmShelfAura and WmShelfMus

ash/mus/bridge/wm_shelf_mus.cc

Index: ash/mus/bridge/wm_shelf_mus.cc
diff --git a/ash/mus/bridge/wm_shelf_mus.cc b/ash/mus/bridge/wm_shelf_mus.cc
deleted file mode 100644
index e368f802554e8508b94b04dd318d1c6c4facb5d6..0000000000000000000000000000000000000000
--- a/ash/mus/bridge/wm_shelf_mus.cc
+++ /dev/null
@@ -1,25 +0,0 @@
-// 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.
-
-#include "ash/mus/bridge/wm_shelf_mus.h"
-
-#include "ash/common/shelf/shelf_widget.h"
-#include "ash/common/wm_root_window_controller.h"
-#include "ash/common/wm_shell.h"
-#include "ash/common/wm_window.h"
-
-namespace ash {
-namespace mus {
-
-WmShelfMus::WmShelfMus() {}
-
-WmShelfMus::~WmShelfMus() {}
-
-void WmShelfMus::WillDeleteShelfLayoutManager() {
-  ShutdownShelfWidget();
-  WmShelf::WillDeleteShelfLayoutManager();
-}
-
-}  // namespace mus
-}  // namespace ash