Revert of Fix flakiness of DesktopDragDropClientAuraX11Tests

ui/views/widget/desktop_aura/x11_move_loop_delegate.h

-// Copyright 2014 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 UI_VIEWS_WIDGET_DESKTOP_AURA_X11_MOVE_LOOP_DELEGATE_H_
-#define UI_VIEWS_WIDGET_DESKTOP_AURA_X11_MOVE_LOOP_DELEGATE_H_
-
-#include <X11/Xlib.h>
-
-namespace views {
-
-// Receives mouse events while the X11MoveLoop is tracking a drag.
-class X11MoveLoopDelegate {
- public:
-  // Called when we receive a motion event.
-  virtual void OnMouseMovement(XMotionEvent* event) = 0;
-
-  // Called when the mouse button is released.
-  virtual void OnMouseReleased() = 0;
-
-  // Called when the user has released the mouse button. The move loop will
-  // release the grab after this has been called.
-  virtual void OnMoveLoopEnded() = 0;
-};
-
-}  // namespace views
-
-#endif  // UI_VIEWS_WIDGET_DESKTOP_AURA_X11_MOVE_LOOP_DELEGATE_H_