Refactor GestureNavigation to eliminate code redundancy

content/browser/web_contents/aura/slidable_wrapper.h

+// Copyright 2015 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 CONTENT_BROWSER_WEB_CONTENTS_AURA_SLIDABLE_WRAPPER_H_
+#define CONTENT_BROWSER_WEB_CONTENTS_AURA_SLIDABLE_WRAPPER_H_
+
+#include "base/memory/scoped_ptr.h"
+#include "ui/aura/window.h"
+#include "ui/gfx/geometry/rect.h"
+#include "ui/gfx/transform.h"
+
+namespace ui {
+class Layer;
+class LayerAnimator;
+}
+
+namespace content {
+
+// Wraps a window or a layer, exposing some of their common API to allow
+// overscroll animations for both cases. For a window, it can either assume its
+// ownership or not.
+class SlidableWrapper {
+ public:
+  // Assumes ownership of the |window|.
+  explicit SlidableWrapper(scoped_ptr<aura::Window> window);
+
+  // Assumes ownership of the |layer|.
+  explicit SlidableWrapper(scoped_ptr<ui::Layer> layer);
+
+  ~SlidableWrapper();
+
+  // Returns a pointer to the underlying layer.
+  ui::Layer* GetLayer();
+
+  // Transfers ownership of the wrapped and owned |layer_|.
+  scoped_ptr<ui::Layer> AcquireLayer();
+
+  // Transfers ownership of the wrapped and owned |owned_window_|.
+  scoped_ptr<aura::Window> AcquireWindow();
+
+  // Returns the wrapped target bounds.
+  gfx::Rect GetBounds();
+
+  // Sets the wrapped target bounds.
+  void SetBounds(const gfx::Rect& bounds);
+
+ private:
+  // The wrapped layer.
+  scoped_ptr<ui::Layer> layer_;
+
+  // The wrapped and window.
+  scoped_ptr<aura::Window> window_;
+
+  DISALLOW_COPY_AND_ASSIGN(SlidableWrapper);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_WEB_CONTENTS_AURA_SLIDABLE_WRAPPER_H_