Move CopyFileHierarchy to a common test namespace and also use it in MoveTreeWorkItemTest.MoveDirec…

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_
+
+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);
+
+}  // namespace test
+
+}  // namespace installer
+
+#endif  // CHROME_INSTALLER_UTIL_INSTALLER_UTIL_TEST_COMMON_H_