Move more dnd related files to ui/base

ui/base/dragdrop/download_file_interface.h

Index: ui/base/dragdrop/download_file_interface.h
===================================================================
--- ui/base/dragdrop/download_file_interface.h	(revision 71798)
+++ ui/base/dragdrop/download_file_interface.h	(working copy)
@@ -1,9 +1,9 @@
-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// 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 APP_DOWNLOAD_FILE_INTERFACE_H_
-#define APP_DOWNLOAD_FILE_INTERFACE_H_
+#ifndef UI_BASE_DRAGDROP_DOWNLOAD_FILE_INTERFACE_H_
+#define UI_BASE_DRAGDROP_DOWNLOAD_FILE_INTERFACE_H_
 #pragma once
 
 #include "build/build_config.h"
@@ -17,6 +17,8 @@
 
 class FilePath;
 
+namespace ui {
+
 // Defines the interface to observe the status of file download.
 class DownloadFileObserver
     : public base::RefCountedThreadSafe<DownloadFileObserver> {
@@ -44,4 +46,6 @@
   virtual ~DownloadFileProvider() {}
 };
 
-#endif  // APP_DOWNLOAD_FILE_INTERFACE_H_
+}  // namespace ui
+
+#endif  // UI_BASE_DRAGDROP_DOWNLOAD_FILE_INTERFACE_H_