Removing PrefObserver usage, batch 4.

chrome/browser/extensions/external_policy_loader.cc

Index: chrome/browser/extensions/external_policy_loader.cc
diff --git a/chrome/browser/extensions/external_policy_loader.cc b/chrome/browser/extensions/external_policy_loader.cc
index 79ddb8dbe8bc7cc192575fadac0fd23fd05ae7e2..6df0304c870a5e1dfe6639d87cfb2028213ad41e 100644
--- a/chrome/browser/extensions/external_policy_loader.cc
+++ b/chrome/browser/extensions/external_policy_loader.cc
@@ -41,7 +41,9 @@ bool CheckExtension(const std::string& id, const std::string& update_url) {
 ExternalPolicyLoader::ExternalPolicyLoader(Profile* profile)
     : profile_(profile) {
   pref_change_registrar_.Init(profile_->GetPrefs());
-  pref_change_registrar_.Add(prefs::kExtensionInstallForceList, this);
+  pref_change_registrar_.Add(prefs::kExtensionInstallForceList,
+                             base::Bind(&ExternalPolicyLoader::StartLoading,
+                                        base::Unretained(this)));
   notification_registrar_.Add(this,
                               chrome::NOTIFICATION_PROFILE_DESTROYED,
                               content::Source<Profile>(profile_));
@@ -88,12 +90,4 @@ void ExternalPolicyLoader::Observe(
   }
 }
 
-void ExternalPolicyLoader::OnPreferenceChanged(PrefServiceBase* service,
-                                               const std::string& pref_name) {
-  if (service == profile_->GetPrefs()) {
-    DCHECK_EQ(std::string(prefs::kExtensionInstallForceList), pref_name);
-    StartLoading();
-  }
-}
-
 }  // namespace extensions