Unbreak unit tests. Revert r7564.

base/file_path.h

 // Copyright (c) 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.
 
 // FilePath is a container for pathnames stored in a platform's native string
 // type, providing containers for manipulation in according with the
 // platform's conventions for pathnames.  It supports the following path
 // types:
 //
 //                   POSIX            Windows
@@ skipping 114 matching lines @@
     return path_ == that.path_;
   }
 
   // Required for some STL containers and operations
   bool operator<(const FilePath& that) const {
     return path_ < that.path_;
   }
 
   const StringType& value() const { return path_; }
 
-  bool empty() const { return path_.empty(); }
-
   // Returns true if |character| is in kSeparators.
   static bool IsSeparator(CharType character);
 
   // Returns a FilePath corresponding to the directory containing the path
   // named by this object, stripping away the file component.  If this object
   // only contains one component, returns a FilePath identifying
   // kCurrentDirectory.  If this object already refers to the root directory,
   // returns a FilePath identifying the root directory.
   FilePath DirName() const;
 
   // Returns a FilePath corresponding to the last path component of this
   // object, either a file or a directory.  If this object already refers to
   // the root directory, returns a FilePath identifying the root directory;
   // this is the only situation in which BaseName will return an absolute path.
-  FilePath BaseName() const;
+  StringType BaseName() const;
 
   // Returns a FilePath by appending a separator and the supplied path
   // component to this object's path.  Append takes care to avoid adding
   // excessive separators if this object's path already ends with a separator.
   // If this object's path is kCurrentDirectory, a new FilePath corresponding
   // only to |component| is returned.  |component| must be a relative path;
   // it is an error to pass an absolute path.
   FilePath Append(const StringType& component) const WARN_UNUSED_RESULT;
   FilePath Append(const FilePath& component) const WARN_UNUSED_RESULT;
 
@@ skipping 52 matching lines @@
 struct hash<FilePath> {
   size_t operator()(const FilePath& f) const {
     return std::tr1::hash<FilePath::StringType>()(f.value());
   }
 };
 
 }  // namespace __gnu_cxx
 #endif  // defined(COMPILER_GCC)
 
 #endif  // BASE_FILE_PATH_H_