Revert "chromeos: Move files in //ash/common to //ash, part 1"

ash/system/tray/tray_event_filter.h

Index: ash/system/tray/tray_event_filter.h
diff --git a/ash/system/tray/tray_event_filter.h b/ash/system/tray/tray_event_filter.h
deleted file mode 100644
index 21e5ebe405900918c8036fd906413672f013ee43..0000000000000000000000000000000000000000
--- a/ash/system/tray/tray_event_filter.h
+++ /dev/null
@@ -1,50 +0,0 @@
-// 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_SYSTEM_TRAY_TRAY_EVENT_FILTER_H_
-#define ASH_SYSTEM_TRAY_TRAY_EVENT_FILTER_H_
-
-#include <set>
-
-#include "base/macros.h"
-#include "ui/views/pointer_watcher.h"
-
-namespace gfx {
-class Point;
-}
-
-namespace ui {
-class PointerEvent;
-}
-
-namespace ash {
-class TrayBubbleWrapper;
-
-// Handles events for a tray bubble, e.g. to close the system tray bubble when
-// the user clicks outside it.
-class TrayEventFilter : public views::PointerWatcher {
- public:
-  TrayEventFilter();
-  ~TrayEventFilter() override;
-
-  void AddWrapper(TrayBubbleWrapper* wrapper);
-  void RemoveWrapper(TrayBubbleWrapper* wrapper);
-
-  // views::PointerWatcher:
-  void OnPointerEventObserved(const ui::PointerEvent& event,
-                              const gfx::Point& location_in_screen,
-                              views::Widget* target) override;
-
- private:
-  void ProcessPressedEvent(const gfx::Point& location_in_screen,
-                           views::Widget* target);
-
-  std::set<TrayBubbleWrapper*> wrappers_;
-
-  DISALLOW_COPY_AND_ASSIGN(TrayEventFilter);
-};
-
-}  // namespace ash
-
-#endif  // ASH_SYSTEM_TRAY_TRAY_EVENT_FILTER_H_