Replace base::CallbackList with base::ObserverList in CastConfigDelegate

chrome/browser/ui/ash/cast_config_delegate_chromeos.cc

Index: chrome/browser/ui/ash/cast_config_delegate_chromeos.cc
diff --git a/chrome/browser/ui/ash/cast_config_delegate_chromeos.cc b/chrome/browser/ui/ash/cast_config_delegate_chromeos.cc
index 2a210710c50458c2628a5fa54a0a0b4d1235c029..84ed24362de7a8e71345d9c9be2fa50a47017e7e 100644
--- a/chrome/browser/ui/ash/cast_config_delegate_chromeos.cc
+++ b/chrome/browser/ui/ash/cast_config_delegate_chromeos.cc
@@ -65,11 +65,15 @@ bool CastConfigDelegateChromeos::HasCastExtension() const {
   return FindCastExtension() != nullptr;
 }
 
-CastConfigDelegateChromeos::DeviceUpdateSubscription
-CastConfigDelegateChromeos::RegisterDeviceUpdateObserver(
-    const ReceiversAndActivitesCallback& callback) {
+void CastConfigDelegateChromeos::AddObserver(
+    ash::CastConfigDelegate::Observer* observer) {
   auto listeners = extensions::CastDeviceUpdateListeners::Get(GetProfile());
-  return listeners->RegisterCallback(callback);
+  return listeners->AddObserver(observer);

[stevenjb, 2016/01/12 23:31:50]

nit: Local is unnecessary

[jdufault, 2016/01/12 23:59:22]

Done.

+}
+void CastConfigDelegateChromeos::RemoveObserver(
+    ash::CastConfigDelegate::Observer* observer) {
+  auto listeners = extensions::CastDeviceUpdateListeners::Get(GetProfile());
+  return listeners->RemoveObserver(observer);

[stevenjb, 2016/01/12 23:31:50]

Local unnecessary

[jdufault, 2016/01/12 23:59:22]

Done.

 }
 
 void CastConfigDelegateChromeos::RequestDeviceRefresh() {