Split PrefService into PrefService, PrefServiceSimple and PrefServiceSyncable.

chrome/browser/extensions/extension_web_ui.h

Index: chrome/browser/extensions/extension_web_ui.h
diff --git a/chrome/browser/extensions/extension_web_ui.h b/chrome/browser/extensions/extension_web_ui.h
index 4d46e8f9e32d605e0129229ed27f4dbcc0608d12..99a29e7ecd96e87b5f9127aa6b4299f9c9a1d329 100644
--- a/chrome/browser/extensions/extension_web_ui.h
+++ b/chrome/browser/extensions/extension_web_ui.h
@@ -21,7 +21,7 @@ namespace extensions {
 class BookmarkManagerPrivateEventRouter;
 }
 
-class PrefService;
+class PrefServiceSyncable;
 class Profile;
 
 // This class implements WebUI for extensions and allows extensions to put UI in
@@ -57,7 +57,7 @@ class ExtensionWebUI : public content::WebUIController {
                                           const base::Value* override);
 
   // Called from BrowserPrefs
-  static void RegisterUserPrefs(PrefService* prefs);
+  static void RegisterUserPrefs(PrefServiceSyncable* prefs);
 
   // Get the favicon for the extension by getting an icon from the manifest.
   // Note. |callback| is always run asynchronously.