mash: switch to the new pref service

chrome/common/chrome_features.cc

Index: chrome/common/chrome_features.cc
diff --git a/chrome/common/chrome_features.cc b/chrome/common/chrome_features.cc
index cb09f4cc2443f012208b0c327f55b88bf2849701..6c8e1cd67cb104dd7271b243b006690ad1a81c26 100644
--- a/chrome/common/chrome_features.cc
+++ b/chrome/common/chrome_features.cc
@@ -4,6 +4,8 @@
 
 #include "chrome/common/chrome_features.h"
 
+#include "base/command_line.h"
+#include "chrome/common/chrome_switches.h"
 #include "extensions/features/features.h"
 #include "ppapi/features/features.h"
 
@@ -306,4 +308,14 @@ const base::Feature kCrosCompUpdates{"CrosCompUpdates",
                                      base::FEATURE_ENABLED_BY_DEFAULT};
 #endif  // defined(OS_CHROMEOS)
 
+bool PrefServiceEnabled() {
+  return base::FeatureList::IsEnabled(features::kPrefService) ||
+#if BUILDFLAG(ENABLE_PACKAGE_MASH_SERVICES)
+         base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
+             switches::kMusConfig) == switches::kMash;
+#else
+         false;
+#endif
+}
+
 }  // namespace features