Revert of mus: Rename .*PointerWatcher.* to .*PointerDownWatcher.*.

ash/pointer_down_watcher_delegate_aura.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.
-
-#include "ash/ash_export.h"
-#include "ash/common/pointer_down_watcher_delegate.h"
-#include "base/macros.h"
-#include "base/observer_list.h"
-#include "ui/events/event_handler.h"
-
-namespace gfx {
-class Point;
-}
-
-namespace ui {
-class LocatedEvent;
-}
-
-namespace views {
-class Widget;
-}
-
-namespace ash {
-
-// Support for PointerDownWatchers in non-mus ash, implemented with a pre-target
-// EventHandler on the Shell.
-class ASH_EXPORT PointerDownWatcherDelegateAura
-    : public PointerDownWatcherDelegate,
-      public ui::EventHandler {
- public:
-  PointerDownWatcherDelegateAura();
-  ~PointerDownWatcherDelegateAura() override;
-
-  // PointerDownWatcherDelegate:
-  void AddPointerDownWatcher(views::PointerDownWatcher* watcher) override;
-  void RemovePointerDownWatcher(views::PointerDownWatcher* watcher) override;
-
-  // ui::EventHandler:
-  void OnMouseEvent(ui::MouseEvent* event) override;
-  void OnTouchEvent(ui::TouchEvent* event) override;
-
- private:
-  gfx::Point GetLocationInScreen(const ui::LocatedEvent& event) const;
-  views::Widget* GetTargetWidget(const ui::LocatedEvent& event) const;
-
-  // Must be empty on destruction.
-  base::ObserverList<views::PointerDownWatcher, true> pointer_down_watchers_;
-
-  DISALLOW_COPY_AND_ASSIGN(PointerDownWatcherDelegateAura);
-};
-
-}  // namespace ash