If possible, use the PathService instead of the --user-data-dir flag directly

chrome/installer/util/auto_launch_util.cc

Index: chrome/installer/util/auto_launch_util.cc
diff --git a/chrome/installer/util/auto_launch_util.cc b/chrome/installer/util/auto_launch_util.cc
index 08be65d79deb2cc186c50816433c9f3dad32348a..5e797ba58713e4f7dc78e2207d68066a96d28e12 100644
--- a/chrome/installer/util/auto_launch_util.cc
+++ b/chrome/installer/util/auto_launch_util.cc
@@ -185,12 +185,19 @@ void SetWillLaunchAtLogin(const base::FilePath& application_path,
 
       const base::CommandLine& command_line =
           *base::CommandLine::ForCurrentProcess();
+
+      // Propagate --user-data-dir if it was specified on the command line.
+      // Retrieve the value from the PathService since some sanitation may have
+      // taken place. There is no need to add it to the command line in the
+      // event that the dir was overridden by Group Policy since the GP override
+      // will be in force when Chrome is launched.
       if (command_line.HasSwitch(switches::kUserDataDir)) {
         cmd_line += ASCIIToUTF16(" --");
         cmd_line += ASCIIToUTF16(switches::kUserDataDir);
         cmd_line += ASCIIToUTF16("=\"");
-        cmd_line +=
-            command_line.GetSwitchValuePath(switches::kUserDataDir).value();
+        base::FilePath user_data_dir;
+        PathService::Get(chrome::DIR_USER_DATA, &user_data_dir);
+        cmd_line += user_data_dir.value();
         cmd_line += ASCIIToUTF16("\"");
       }