Move more dnd related files to ui/base

app/win/drag_source.cc

-// 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.
-
-#include "app/win/drag_source.h"
-
-namespace app {
-namespace win {
-
-DragSource::DragSource() : cancel_drag_(false) {
-}
-
-HRESULT DragSource::QueryContinueDrag(BOOL escape_pressed, DWORD key_state) {
-  if (cancel_drag_)
-    return DRAGDROP_S_CANCEL;
-
-  if (escape_pressed) {
-    OnDragSourceCancel();
-    return DRAGDROP_S_CANCEL;
-  }
-
-  if (!(key_state & MK_LBUTTON)) {
-    OnDragSourceDrop();
-    return DRAGDROP_S_DROP;
-  }
-
-  OnDragSourceMove();
-  return S_OK;
-}
-
-HRESULT DragSource::GiveFeedback(DWORD effect) {
-  return DRAGDROP_S_USEDEFAULTCURSORS;
-}
-
-HRESULT DragSource::QueryInterface(const IID& iid, void** object) {
-  *object = NULL;
-  if (IsEqualIID(iid, IID_IUnknown) || IsEqualIID(iid, IID_IDropSource)) {
-    *object = this;
-  } else {
-    return E_NOINTERFACE;
-  }
-  AddRef();
-  return S_OK;
-}
-
-ULONG DragSource::AddRef() {
-  base::RefCountedThreadSafe<DragSource>::AddRef();
-  return 0;
-}
-
-ULONG DragSource::Release() {
-  base::RefCountedThreadSafe<DragSource>::Release();
-  return 0;
-}
-
-}  // namespace win
-}  // namespace app