Add FilePath to base namespace.

chrome/installer/util/installer_util_test_common.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 CHROME_INSTALLER_UTIL_INSTALLER_UTIL_TEST_COMMON_H_
 #define CHROME_INSTALLER_UTIL_INSTALLER_UTIL_TEST_COMMON_H_
 
+namespace base {
 class FilePath;
+}
 
 namespace installer {
 
 namespace test {
 
 // Copies the hierarcy in |from| to |to|.
 // Keeps all file properties identical (creation time, etc.).
-bool CopyFileHierarchy(const FilePath& from, const FilePath& to);
+bool CopyFileHierarchy(const base::FilePath& from, const base::FilePath& to);
 
 }  // namespace test
 
 }  // namespace installer
 
 #endif  // CHROME_INSTALLER_UTIL_INSTALLER_UTIL_TEST_COMMON_H_