Split PrefService into PrefService, PrefServiceSimple and PrefServiceSyncable.

chrome/browser/ui/webui/instant_ui.h

Index: chrome/browser/ui/webui/instant_ui.h
diff --git a/chrome/browser/ui/webui/instant_ui.h b/chrome/browser/ui/webui/instant_ui.h
index 5750c435aca8d40ccc5eaeffb324aa58eae7ab8e..8a5cbae72a9d92e479fb750accc1ed37e35914e1 100644
--- a/chrome/browser/ui/webui/instant_ui.h
+++ b/chrome/browser/ui/webui/instant_ui.h
@@ -7,7 +7,7 @@
 
 #include "content/public/browser/web_ui_controller.h"
 
-class PrefService;
+class PrefServiceSyncable;
 
 namespace content {
 class BrowserContext;
@@ -20,7 +20,7 @@ class InstantUI : public content::WebUIController {
   // handlers.
   explicit InstantUI(content::WebUI* web_ui);
 
-  static void RegisterUserPrefs(PrefService* user_prefs);
+  static void RegisterUserPrefs(PrefServiceSyncable* user_prefs);
 
  private:
   DISALLOW_COPY_AND_ASSIGN(InstantUI);