Make file_util::CreateDirectory return an error, not just a bool

base/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.
 
 // This file contains utility functions for dealing with the local
 // filesystem.
 
 #ifndef BASE_FILE_UTIL_H_
 #define BASE_FILE_UTIL_H_
 
@@ skipping 251 matching lines @@
 // Extra characters will be appended to |prefix| to ensure that the
 // new directory does not have the same name as an existing directory.
 BASE_EXPORT bool CreateTemporaryDirInDir(
     const base::FilePath& base_dir,
     const base::FilePath::StringType& prefix,
     base::FilePath* new_dir);
 
 // Creates a directory, as well as creating any parent directories, if they
 // don't exist. Returns 'true' on successful creation, or if the directory
 // already exists.  The directory is only readable by the current user.
+// Returns true on success, leaving *error unchanged.
+// Returns false on failure and sets *error appropriately, if it is non-NULL.
+BASE_EXPORT bool CreateDirectoryAndGetError(const base::FilePath& full_path,
+                                            base::PlatformFileError* error);
+
+// Backward-compatible convenience method for the above.
 BASE_EXPORT bool CreateDirectory(const base::FilePath& full_path);
 
 // Returns the file size. Returns true on success.
 BASE_EXPORT bool GetFileSize(const base::FilePath& file_path, int64* file_size);
 
 // Sets |real_path| to |path| with symbolic links and junctions expanded.
 // On windows, make sure the path starts with a lettered drive.
 // |path| must reference a file.  Function will fail if |path| points to
 // a directory or to a nonexistent path.  On windows, this function will
 // fail if |path| is a junction or symlink that points to an empty file,
@@ skipping 162 matching lines @@
 
 // Attempts determine the FileSystemType for |path|.
 // Returns false if |path| doesn't exist.
 BASE_EXPORT bool GetFileSystemType(const base::FilePath& path,
                                    FileSystemType* type);
 #endif
 
 }  // namespace file_util
 
 #endif  // BASE_FILE_UTIL_H_