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

chrome/app/chrome_main_delegate.cc

Index: chrome/app/chrome_main_delegate.cc
diff --git a/chrome/app/chrome_main_delegate.cc b/chrome/app/chrome_main_delegate.cc
index 3b56ecfa1e9af06373b437e570738278b7873497..0f385753bd47f012b2325239a176565e126e3e96 100644
--- a/chrome/app/chrome_main_delegate.cc
+++ b/chrome/app/chrome_main_delegate.cc
@@ -345,10 +345,8 @@ void InitializeUserDataDir() {
 
   // On Windows, trailing separators leave Chrome in a bad state.
   // See crbug.com/464616.
-  if (user_data_dir.EndsWithSeparator()) {
+  if (user_data_dir.EndsWithSeparator())
     user_data_dir = user_data_dir.StripTrailingSeparators();
-    command_line->AppendSwitchPath(switches::kUserDataDir, user_data_dir);
-  }
 
   const bool specified_directory_was_invalid = !user_data_dir.empty() &&
       !PathService::OverrideAndCreateIfNeeded(chrome::DIR_USER_DATA,