First shot at implementing drag&drop for Aura

ui/aura/drag_drop_controller.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_AURA_DRAG_DROP_CONTROLLER_H_
+#define UI_AURA_DRAG_DROP_CONTROLLER_H_
+#pragma once
+
+#include "ui/aura/aura_export.h"
+#include "ui/aura/event.h"
+#include "ui/base/dragdrop/os_exchange_data.h"
+#include "ui/gfx/point.h"
+
+namespace aura {
+
+class MouseEvent;
+
+class AURA_EXPORT DragDropController {
+ public:
+  virtual ~DragDropController() {}
+
+  virtual void StartDragAndDrop(const ui::OSExchangeData& data,
+                                int operation,
+                                const gfx::Point& location) = 0;
+
+  virtual void DragUpdate(const MouseEvent& event) = 0;
+
+  virtual void Drop(const MouseEvent& event) = 0;
+};
+
+}  // namespace aura
+
+#endif  // UI_AURA_DRAG_DROP_CONTROLLER_H_