Fix some includes in CopyOrMoveFileValidator code.

webkit/fileapi/copy_or_move_file_validator.h

 // Copyright 2013 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 WEBKIT_FILEAPI_COPY_OR_MOVE_FILE_VALIDATOR_H_
 #define WEBKIT_FILEAPI_COPY_OR_MOVE_FILE_VALIDATOR_H_
 
 #include "base/callback.h"
-#include "base/files/file_path.h"
 #include "base/platform_file.h"
 
+namespace base {
+class FilePath;
+}
+
 namespace fileapi {
 
+class FileSystemURL;
+
 class CopyOrMoveFileValidator {
  public:
   // Callback that is invoked when validation completes. A result of
   // base::PLATFORM_FILE_OK means the file validated.
   typedef base::Callback<void(base::PlatformFileError result)> ResultCallback;
 
   virtual ~CopyOrMoveFileValidator() {}
 
   virtual void StartValidation(const ResultCallback& result_callback) = 0;
 };
 
 class CopyOrMoveFileValidatorFactory {
  public:
   virtual ~CopyOrMoveFileValidatorFactory() {}
 
   // This method must always return a non-NULL validator. |src_url| is needed
   // in addition to |platform_path| because in the obfuscated file system
   // case, |platform_path| will be an obfuscated filename and extension.
   virtual CopyOrMoveFileValidator* CreateCopyOrMoveFileValidator(
       const FileSystemURL& src_url,
       const base::FilePath& platform_path) = 0;
 };
 
 }  // namespace fileapi
 
 #endif  // WEBKIT_FILEAPI_COPY_OR_MOVE_FILE_VALIDATOR_H_