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

ui/views/controls/slide_out_view.h

Index: ui/views/controls/slide_out_view.h
diff --git a/ui/views/controls/slide_out_view.h b/ui/views/controls/slide_out_view.h
new file mode 100644
index 0000000000000000000000000000000000000000..89962f2d317f40cb1f9be1a5f43e07179ae70725
--- /dev/null
+++ b/ui/views/controls/slide_out_view.h
@@ -0,0 +1,58 @@
+// 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_