[app_installer] Refactor and add app_installer_unittests target.

chrome/app_installer/win/app_installer_util.h

+// Copyright 2014 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_APP_INSTALLER_WIN_APP_INSTALLER_UTIL_H_
+#define CHROME_APP_INSTALLER_WIN_APP_INSTALLER_UTIL_H_
+
+#include <map>
+#include <string>
+
+#include "base/files/file_path.h"
+
+namespace app_installer {
+
+extern const char kInstallChromeApp[];
+
+enum ExitCode {
+  SUCCESS = 0,
+  COULD_NOT_GET_FILE_PATH,
+  COULD_NOT_READ_TAG,
+  COULD_NOT_PARSE_TAG,
+  INVALID_APP_ID,
+  EULA_CANCELLED,
+  COULD_NOT_FIND_CHROME,
+  COULD_NOT_GET_TMP_FILE_PATH,
+  FAILED_TO_DOWNLOAD_CHROME_SETUP,
+  FAILED_TO_LAUNCH_CHROME_SETUP,
+};
+
+// Gets the tag attached to a file by dl.google.com. This uses the same format
+// as Omaha. Returns the empty string on failure.
+std::string GetTag(const base::FilePath& file_name_path);
+
+// Parses |tag| as key-value pairs and overwrites |parsed_pairs| with
+// the result. |tag| should be a '&'-delimited list of '='-separated
+// key-value pairs, e.g. "key1=value1&key2=value2".
+// Returns true if the data could be parsed.
+bool ParseTag(const std::string& tag,
+              std::map<std::string, std::string>* parsed_pairs);
+
+bool IsValidAppId(const std::string& app_id);
+
+base::FilePath GetChromeExePath(bool is_canary);
+
+// Shows UI to download and install Chrome. Returns a failure code, or SUCCESS
+// if the installation completed successfully.
+ExitCode GetChrome(bool is_canary);
+
+}  // namespace app_installer
+
+#endif  // CHROME_APP_INSTALLER_WIN_APP_INSTALLER_UTIL_H_