Show user data dialog earlier on Windows.

chrome/browser/user_data_dir_extractor_win.h

+// Copyright (c) 2013 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_BROWSER_USER_DATA_DIR_EXTRACTOR_WIN_H_
+#define CHROME_BROWSER_USER_DATA_DIR_EXTRACTOR_WIN_H_
+
+#include "base/callback.h"
+
+namespace chrome {
+
+// Tests can call this to install a custom callback to be called instead of
+// actually showing the dialog when ShowUserDataDirDialog() is invoked.
+void InstallCustomShowUserDataDirDialogCallbackForTest(base::Closure* callback);
+
+}  // namespace chrome
+
+#endif  // CHROME_BROWSER_USER_DATA_DIR_EXTRACTOR_WIN_H_