It is time.

ui/views/controls/resize_area.h

-// Copyright (c) 2011 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_CONTROLS_RESIZE_AREA_H_
-#define UI_VIEWS_CONTROLS_RESIZE_AREA_H_
-
-#include <string>
-
-#include "ui/views/view.h"
-
-namespace views {
-
-class ResizeAreaDelegate;
-
-////////////////////////////////////////////////////////////////////////////////
-//
-// An invisible area that acts like a horizontal resizer.
-//
-////////////////////////////////////////////////////////////////////////////////
-class VIEWS_EXPORT ResizeArea : public View {
- public:
-  static const char kViewClassName[];
-
-  explicit ResizeArea(ResizeAreaDelegate* delegate);
-  virtual ~ResizeArea();
-
-  // Overridden from views::View:
-  virtual const char* GetClassName() const override;
-  virtual gfx::NativeCursor GetCursor(const ui::MouseEvent& event) override;
-  virtual bool OnMousePressed(const ui::MouseEvent& event) override;
-  virtual bool OnMouseDragged(const ui::MouseEvent& event) override;
-  virtual void OnMouseReleased(const ui::MouseEvent& event) override;
-  virtual void OnMouseCaptureLost() override;
-  virtual void GetAccessibleState(ui::AXViewState* state) override;
-
- private:
-  // Report the amount the user resized by to the delegate, accounting for
-  // directionality.
-  void ReportResizeAmount(int resize_amount, bool last_update);
-
-  // The delegate to notify when we have updates.
-  ResizeAreaDelegate* delegate_;
-
-  // The mouse position at start (in screen coordinates).
-  int initial_position_;
-
-  DISALLOW_COPY_AND_ASSIGN(ResizeArea);
-};
-
-}  // namespace views
-
-#endif  // UI_VIEWS_CONTROLS_RESIZE_AREA_H_