chromeos: Move files in //ash/common to //ash, part 2

ash/common/metrics/task_switch_source.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_METRICS_TASK_SWITCH_SOURCE_H_
-#define ASH_COMMON_METRICS_TASK_SWITCH_SOURCE_H_
-
-namespace ash {
-
-// Enumeration of the different user interfaces that could be the source of
-// a task switch. Note this is not necessarily comprehensive of all sources.
-enum class TaskSwitchSource {
-  // Task switches caused by any two sources in this enum. NOTE: This value
-  // should NOT be used outside of TaskSwitchMetricsRecorder.
-  ANY,
-  // Task switches caused by the user activating a task window by clicking or
-  // tapping on it.
-  DESKTOP,
-  // Task switches caused by selecting a window from overview mode which is
-  // different from the previously-active window.
-  OVERVIEW_MODE,
-  // All task switches caused by shelf buttons, not including sub-menus.
-  SHELF,
-  // Task switches caused by the WindowCycleController (ie Alt+Tab).
-  WINDOW_CYCLE_CONTROLLER
-};
-
-}  // namespace ash
-
-#endif  // ASH_COMMON_METRICS_TASK_SWITCH_SOURCE_H_