reland "CrOS: Fix appearance of notification toasts when sliding out via gesture"

ui/views/controls/slide_out_view.h

-// 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 UI_VIEWS_CONTROLS_SLIDE_OUT_VIEW_H_
-#define UI_VIEWS_CONTROLS_SLIDE_OUT_VIEW_H_
-
-#include "base/macros.h"
-#include "ui/compositor/layer_animation_observer.h"
-#include "ui/views/view.h"
-#include "ui/views/views_export.h"
-
-namespace views {
-
-// A View that can be closed by a slide-out touch gesture.
-class VIEWS_EXPORT SlideOutView : public views::View,
-                                  public ui::ImplicitAnimationObserver {
- public:
-  SlideOutView();
-  ~SlideOutView() override;
-
-  bool slide_out_enabled() { return is_slide_out_enabled_; }
-
- protected:
-  // Called when user intends to close the View by sliding it out.
-  virtual void OnSlideOut() = 0;
-
-  // Overridden from views::View.
-  void OnGestureEvent(ui::GestureEvent* event) override;
-
-  void set_slide_out_enabled(bool is_slide_out_enabled) {
-    is_slide_out_enabled_ = is_slide_out_enabled;
-  }
-
- private:
-  enum SlideDirection {
-    SLIDE_LEFT,
-    SLIDE_RIGHT,
-  };
-
-  // Restores the transform and opacity of the view.
-  void RestoreVisualState();
-
-  // Slides the view out and closes it after the animation.
-  void SlideOutAndClose(SlideDirection direction);
-
-  // Overridden from ImplicitAnimationObserver.
-  void OnImplicitAnimationsCompleted() override;
-
-  float gesture_amount_ = 0.f;
-  bool is_slide_out_enabled_ = true;
-
-  DISALLOW_COPY_AND_ASSIGN(SlideOutView);
-};
-
-}  // namespace views
-
-#endif  // UI_VIEWS_CONTROLS_SLIDE_OUT_VIEW_H_