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

chrome/browser/extensions/api/cast_devices_private/cast_devices_private_api.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/extensions/api/cast_devices_private/cast_devices_private_api.h"
 
 #include "base/lazy_instance.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/common/extensions/api/cast_devices_private.h"
 
@@ skipping 47 matching lines @@
 CastDeviceUpdateListeners* CastDeviceUpdateListeners::Get(
     content::BrowserContext* context) {
   return BrowserContextKeyedAPIFactory<CastDeviceUpdateListeners>::Get(context);
 }
 
 CastDeviceUpdateListeners::CastDeviceUpdateListeners(
     content::BrowserContext* context) {}
 
 CastDeviceUpdateListeners::~CastDeviceUpdateListeners() {}
 
-ash::CastConfigDelegate::DeviceUpdateSubscription
-CastDeviceUpdateListeners::RegisterCallback(
-    const ash::CastConfigDelegate::ReceiversAndActivitesCallback& callback) {
-  return callback_list_.Add(callback);
+void CastDeviceUpdateListeners::AddObserver(
+    ash::CastConfigDelegate::Observer* observer) {
+  observer_list_.AddObserver(observer);
+}
+
+void CastDeviceUpdateListeners::RemoveObserver(
+    ash::CastConfigDelegate::Observer* observer) {
+  observer_list_.RemoveObserver(observer);
 }
 
 void CastDeviceUpdateListeners::NotifyCallbacks(
     const ReceiverAndActivityList& devices) {
-  callback_list_.Notify(devices);
+  FOR_EACH_OBSERVER(ash::CastConfigDelegate::Observer, observer_list_,
+                    OnDevicesUpdated(devices));
 }
 
 CastDevicesPrivateUpdateDevicesFunction::
     CastDevicesPrivateUpdateDevicesFunction() {}
 
 CastDevicesPrivateUpdateDevicesFunction::
     ~CastDevicesPrivateUpdateDevicesFunction() {}
 
 ExtensionFunction::ResponseAction
 CastDevicesPrivateUpdateDevicesFunction::Run() {
   auto params =
       api::cast_devices_private::UpdateDevices::Params::Create(*args_);
 
   CastDeviceUpdateListeners::ReceiverAndActivityList devices;
   for (linked_ptr<api::cast_devices_private::ReceiverActivity> device :
        params->devices) {
     devices.push_back(ConvertReceiverAndActivityType(device->receiver,
                                                      device->activity.get()));
   }
 
   auto listeners = CastDeviceUpdateListeners::Get(browser_context());
   listeners->NotifyCallbacks(devices);
 
   return RespondNow(NoArguments());
 }
 
 }  // namespace extensions