Move more dnd related files to ui/base

app/win/drag_source.h

-// Copyright (c) 2010 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 APP_WIN_DRAG_SOURCE_H_
-#define APP_WIN_DRAG_SOURCE_H_
-#pragma once
-
-#include <objidl.h>
-
-#include "base/basictypes.h"
-#include "base/ref_counted.h"
-
-namespace app {
-namespace win {
-
-// A base IDropSource implementation. Handles notifications sent by an active
-// drag-drop operation as the user mouses over other drop targets on their
-// system. This object tells Windows whether or not the drag should continue,
-// and supplies the appropriate cursors.
-class DragSource : public IDropSource,
-                   public base::RefCountedThreadSafe<DragSource> {
- public:
-  DragSource();
-  virtual ~DragSource() {}
-
-  // Stop the drag operation at the next chance we get.  This doesn't
-  // synchronously stop the drag (since Windows is controlling that),
-  // but lets us tell Windows to cancel the drag the next chance we get.
-  void CancelDrag() {
-    cancel_drag_ = true;
-  }
-
-  // IDropSource implementation:
-  HRESULT __stdcall QueryContinueDrag(BOOL escape_pressed, DWORD key_state);
-  HRESULT __stdcall GiveFeedback(DWORD effect);
-
-  // IUnknown implementation:
-  HRESULT __stdcall QueryInterface(const IID& iid, void** object);
-  ULONG __stdcall AddRef();
-  ULONG __stdcall Release();
-
- protected:
-  virtual void OnDragSourceCancel() {}
-  virtual void OnDragSourceDrop() {}
-  virtual void OnDragSourceMove() {}
-
- private:
-  // Set to true if we want to cancel the drag operation.
-  bool cancel_drag_;
-
-  DISALLOW_COPY_AND_ASSIGN(DragSource);
-};
-
-}  // namespace win
-}  // namespace app
-
-#endif  // APP_WIN_DRAG_SOURCE_H_