Return an approximately correct drop effect from WebDragTarget::OnDrop.

chrome/browser/tab_contents/web_drag_utils_win.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 "chrome/browser/tab_contents/web_drag_utils_win.h"
 
 #include <oleidl.h>
 
 using WebKit::WebDragOperationsMask;
 using WebKit::WebDragOperationNone;
 using WebKit::WebDragOperationCopy;
 using WebKit::WebDragOperationLink;
 using WebKit::WebDragOperationMove;
 
 namespace web_drag_utils_win {
 
 WebDragOperationsMask WinDragOpToWebDragOp(DWORD effect) {
   WebDragOperationsMask op = WebDragOperationNone;
   if (effect & DROPEFFECT_COPY)
     op = static_cast<WebDragOperationsMask>(op | WebDragOperationCopy);
   if (effect & DROPEFFECT_LINK)
     op = static_cast<WebDragOperationsMask>(op | WebDragOperationLink);
   if (effect & DROPEFFECT_MOVE)
     op = static_cast<WebDragOperationsMask>(op | WebDragOperationMove);
   return op;
 }
 
+DWORD WebDragOpToWinDragOp(WebDragOperationsMask op) {
+  DWORD win_op = DROPEFFECT_NONE;
+  if (op & WebDragOperationCopy)
+    win_op |= DROPEFFECT_COPY;
+  if (op & WebDragOperationLink)
+    win_op |= DROPEFFECT_LINK;
+  if (op & WebDragOperationMove)
+    win_op |= DROPEFFECT_MOVE;
+  return win_op;
+}
+
 }  // namespace web_drag_utils_win