Split recursive Copy/Move into async tasks and support cross operation (in local case)

webkit/fileapi/file_system_file_util.h

 // Copyright (c) 2012 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_FILE_SYSTEM_FILE_UTIL_H_
 #define WEBKIT_FILEAPI_FILE_SYSTEM_FILE_UTIL_H_
 
 #include "base/file_path.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/platform_file.h"
@@ skipping 141 matching lines @@
   // current length of the file, the file will be extended with zeroes.
   virtual base::PlatformFileError Truncate(
       FileSystemOperationContext* context,
       const FileSystemURL& url,
       int64 length) = 0;
 
   // Copies or moves a single file from |src_url| to |dest_url|.
   // The filesystem type of |src_url| and |dest_url| MUST be same.
   //
   // This returns:
-  // - PLATFORM_FILE_ERROR_NOT_FOUND if |src_file_path|
+  // - PLATFORM_FILE_ERROR_NOT_FOUND if |src_url|
   //   or the parent directory of |dest_url| does not exist.
   // - PLATFORM_FILE_ERROR_NOT_A_FILE if |src_url| exists but is not a file.
   // - PLATFORM_FILE_ERROR_INVALID_OPERATION if |dest_url| exists and
   //   is not a file.
   // - PLATFORM_FILE_ERROR_FAILED if |dest_url| does not exist and
   //   its parent path is a file.
   //
   virtual base::PlatformFileError CopyOrMoveFile(
       FileSystemOperationContext* context,
       const FileSystemURL& src_url,
@@ skipping 46 matching lines @@
   //
   // |file_info| is the metadata of the snapshot file created.
   // |platform_path| is the path to the snapshot file created.
   // |policy| should indicate the policy how the fileapi backend
   // should handle the returned file.
   //
   // This returns:
   // - PLATFORM_FILE_ERROR_NOT_FOUND if |url| does not exist.
   // - PLATFORM_FILE_ERROR_NOT_A_FILE if |url| is not a file.
   //
+  // The field values of |file_info| are undefined (implementation
+  // dependent) in error cases, and the caller should always
+  // check the return code.
+  //
   virtual base::PlatformFileError CreateSnapshotFile(
       FileSystemOperationContext* context,
       const FileSystemURL& url,
       base::PlatformFileInfo* file_info,
       FilePath* platform_path,
       SnapshotFilePolicy* policy) = 0;
 
  protected:
   FileSystemFileUtil() {}
 
  private:
   DISALLOW_COPY_AND_ASSIGN(FileSystemFileUtil);
 };
 
 }  // namespace fileapi
 
 #endif  // WEBKIT_FILEAPI_FILE_SYSTEM_FILE_UTIL_H_