Add FilePath to base namespace.

ui/base/dragdrop/download_file_interface.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_BASE_DRAGDROP_DOWNLOAD_FILE_INTERFACE_H_
 #define UI_BASE_DRAGDROP_DOWNLOAD_FILE_INTERFACE_H_
 
 #include "build/build_config.h"
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 
 #include "ui/base/ui_export.h"
 
 #if defined(OS_WIN)
 #include <objidl.h>
 #endif
 
+namespace base {
 class FilePath;
+}
 
 namespace ui {
 
 // TODO(benjhayden, anybody): Do these need to be RefCountedThreadSafe?
 
 // Defines the interface to observe the status of file download.
 class UI_EXPORT DownloadFileObserver
     : public base::RefCountedThreadSafe<DownloadFileObserver> {
  public:
   virtual void OnDownloadCompleted(const FilePath& file_path) = 0;
@@ skipping 19 matching lines @@
   virtual void Stop() = 0;
 
  protected:
   friend class base::RefCountedThreadSafe<DownloadFileProvider>;
   virtual ~DownloadFileProvider() {}
 };
 
 }  // namespace ui
 
 #endif  // UI_BASE_DRAGDROP_DOWNLOAD_FILE_INTERFACE_H_