Cleanup PreferenceMACs on browser_tests startup

base/files/scoped_temp_dir.h

 // Copyright (c) 2011 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 BASE_FILES_SCOPED_TEMP_DIR_H_
 #define BASE_FILES_SCOPED_TEMP_DIR_H_
 
 // An object representing a temporary / scratch directory that should be cleaned
 // up (recursively) when this object goes out of scope.  Note that since
 // deletion occurs during the destructor, no further error handling is possible
@@ skipping 36 matching lines @@
   // when this object goes out of scope.
   FilePath Take();
 
   // Returns the path to the created directory. Call one of the
   // CreateUniqueTempDir* methods before getting the path.
   const FilePath& GetPath() const;
 
   // Returns true if path_ is non-empty and exists.
   bool IsValid() const;
 
+  // Returns the prefix used for temp directory names generated by
+  // ScopedTempDirs.
+  static const FilePath::CharType* GetTempDirPrefix();
+
  private:
   FilePath path_;
 
   DISALLOW_COPY_AND_ASSIGN(ScopedTempDir);
 };
 
 }  // namespace base
 
 #endif  // BASE_FILES_SCOPED_TEMP_DIR_H_