Fix the case where the browser livelocks if we cannot open a file.

base/file_util.h

 // Copyright (c) 2006-2008 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 143 matching lines @@
 bool CopyDirectory(const FilePath& from_path, const FilePath& to_path,
                    bool recursive);
 // Deprecated temporary compatibility function.
 bool CopyDirectory(const std::wstring& from_path, const std::wstring& to_path,
                    bool recursive);
 
 // Returns true if the given path exists on the local filesystem,
 // false otherwise.
 bool PathExists(const FilePath& path);
 
+// Returns true if the given path is readable by the user, false otherwise.
+bool PathIsReadable(const FilePath& path);
+
 // Returns true if the given path is writable by the user, false otherwise.
 bool PathIsWritable(const FilePath& path);
 
 // Returns true if the given path exists and is a directory, false otherwise.
 bool DirectoryExists(const FilePath& path);
 
 #if defined(OS_WIN)
 // Gets the creation time of the given file (expressed in the local timezone),
 // and returns it via the creation_time parameter.  Returns true if successful,
 // false otherwise.
@@ skipping 369 matching lines @@
     const FilePath& source_file_path,
     const FilePath& target_file_path);
 
 // Returns whether the file has been modified since a particular date.
 bool HasFileBeenModifiedSince(const FileEnumerator::FindInfo& find_info,
                               const base::Time& cutoff_time);
 
 }  // namespace file_util
 
 #endif  // BASE_FILE_UTIL_H_