Remove PrefServiceSimple, replacing it with PrefService and PrefRegistrySimple.

chrome/browser/chromeos/audio/audio_handler.h

Index: chrome/browser/chromeos/audio/audio_handler.h
diff --git a/chrome/browser/chromeos/audio/audio_handler.h b/chrome/browser/chromeos/audio/audio_handler.h
index 78b333ba6d9915984c3a3688854c038aae4e6304..8675371bbf24d47b8e0c635b21e463f40bc686a1 100644
--- a/chrome/browser/chromeos/audio/audio_handler.h
+++ b/chrome/browser/chromeos/audio/audio_handler.h
@@ -14,8 +14,8 @@
 template <typename T> struct DefaultSingletonTraits;
 
 class PrefChangeRegistrar;
+class PrefRegistrarSimple;
 class PrefService;
-class PrefServiceSimple;
 
 namespace chromeos {
 
@@ -44,7 +44,7 @@ class AudioHandler {
   static AudioHandler* GetInstance();
 
   // Registers volume and mute preferences.
-  static void RegisterPrefs(PrefServiceSimple* local_state);
+  static void RegisterPrefs(PrefRegistrarSimple* local_state);
 
   // Gets volume level in our internal 0-100% range, 0 being pure silence.
   double GetVolumePercent();