Remove PrefServiceSimple, replacing it with PrefService and PrefRegistrySimple.

chrome/browser/metrics/metrics_service.h

Index: chrome/browser/metrics/metrics_service.h
diff --git a/chrome/browser/metrics/metrics_service.h b/chrome/browser/metrics/metrics_service.h
index 08c6080ef18365746e63964e9864e1aa1c4f89c7..9cd2bef42606e2dd333c8aaa3ce79b47b191c3fb 100644
--- a/chrome/browser/metrics/metrics_service.h
+++ b/chrome/browser/metrics/metrics_service.h
@@ -32,7 +32,7 @@
 
 class MetricsReportingScheduler;
 class PrefService;
-class PrefServiceSimple;
+class PrefRegistrySimple;
 class Profile;
 class TemplateURLService;
 
@@ -122,7 +122,7 @@ class MetricsService
 
   // At startup, prefs needs to be called with a list of all the pref names and
   // types we'll be using.
-  static void RegisterPrefs(PrefServiceSimple* local_state);
+  static void RegisterPrefs(PrefRegistrySimple* local_state);
 
   // Set up notifications which indicate that a user is performing work. This is
   // useful to allow some features to sleep, until the machine becomes active,