chromeos: Remove some IME methods from ash::SystemTrayDelegate

ash/ime/ime_switch_type.h

+// Copyright 2017 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_IME_IME_SWITCH_TYPE_H_
+#define ASH_IME_IME_SWITCH_TYPE_H_
+
+namespace ash {
+
+// Used for histograms. See tools/metrics/histograms/enums.xml IMESwitchType.
+enum class ImeSwitchType {
+  // The values should not reordered or deleted and new entries should only be
+  // added at the end (otherwise it will cause problems interpreting logs)
+  kTray = 0,
+  kAccelerator = 1,
+  kCount = 2,
+};
+
+}  // namespace ash
+
+#endif  // ASH_IME_IME_SWITCH_TYPE_H_