Removing PrefObserver usage, batch 4.

chrome/browser/extensions/external_policy_loader.h

Index: chrome/browser/extensions/external_policy_loader.h
diff --git a/chrome/browser/extensions/external_policy_loader.h b/chrome/browser/extensions/external_policy_loader.h
index 44f9f1b1cdf6d89d500da2419cd8bb1e090fbb93..bd0f5f5684d132ecc79eb6704708783c205b4592 100644
--- a/chrome/browser/extensions/external_policy_loader.h
+++ b/chrome/browser/extensions/external_policy_loader.h
@@ -9,7 +9,6 @@
 
 #include "base/compiler_specific.h"
 #include "base/prefs/public/pref_change_registrar.h"
-#include "base/prefs/public/pref_observer.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 
@@ -22,8 +21,7 @@ namespace extensions {
 // registered.
 class ExternalPolicyLoader
     : public ExternalLoader,
-      public content::NotificationObserver,
-      public PrefObserver {
+      public content::NotificationObserver {
  public:
   explicit ExternalPolicyLoader(Profile* profile);
 
@@ -32,10 +30,6 @@ class ExternalPolicyLoader
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
 
-  // PrefObserver implementation
-  virtual void OnPreferenceChanged(PrefServiceBase* service,
-                                   const std::string& pref_name) OVERRIDE;
-
  protected:
   virtual void StartLoading() OVERRIDE;