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

chrome/installer/util/installer_util_test_common.cc

+// 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.
+
+#include "chrome/installer/util/installer_util_test_common.h"
+
+#include <windows.h>
+#include <shellapi.h>
+
+#include "base/file_path.h"
+#include "base/string16.h"
+
+namespace installer {
+
+namespace test {
+
+bool CopyFileHierarchy(const FilePath& from, const FilePath& to) {
+  // In SHFILEOPSTRUCT below, |pFrom| and |pTo| have to be double-null
+  // terminated: http://msdn.microsoft.com/library/bb759795.aspx
+  string16 double_null_from(from.value());
+  double_null_from.push_back(L'\0');
+  string16 double_null_to(to.value());
+  double_null_to.push_back(L'\0');
+
+  SHFILEOPSTRUCT file_op = {};
+  file_op.wFunc = FO_COPY;
+  file_op.pFrom = double_null_from.c_str();
+  file_op.pTo = double_null_to.c_str();
+  file_op.fFlags = FOF_NO_UI;
+
+  return (SHFileOperation(&file_op) == 0 && !file_op.fAnyOperationsAborted);
+}
+
+}  // namespace test
+
+}  // namespace installer