Refactor MessageCenterSettingsController.

chrome/browser/notifications/message_center_settings_controller.cc

Index: chrome/browser/notifications/message_center_settings_controller.cc
diff --git a/chrome/browser/notifications/message_center_settings_controller.cc b/chrome/browser/notifications/message_center_settings_controller.cc
index 1e0dc01b34d2f02d8a6ef774ff4e0367cd97e305..3bbb7c4ac5a076d671c14a4b29c7c4dfba1bf64a 100644
--- a/chrome/browser/notifications/message_center_settings_controller.cc
+++ b/chrome/browser/notifications/message_center_settings_controller.cc
@@ -20,6 +20,7 @@
 #include "chrome/browser/extensions/extension_app_icon_loader.h"
 #include "chrome/browser/favicon/favicon_service_factory.h"
 #include "chrome/browser/notifications/desktop_notification_profile_util.h"
+#include "chrome/browser/notifications/notifier_source.h"
 #include "chrome/browser/notifications/notifier_state_tracker.h"
 #include "chrome/browser/notifications/notifier_state_tracker_factory.h"
 #include "chrome/browser/profiles/profile.h"
@@ -49,8 +50,7 @@
 #if defined(OS_CHROMEOS)
 #include "ash/system/system_notifier.h"
 #include "chrome/browser/chromeos/profiles/profile_helper.h"
-#include "chrome/browser/notifications/arc_notifier_manager.h"
-#include "components/arc/arc_bridge_service.h"
+#include "chrome/browser/notifications/arc_notifier_source.h"
 #endif
 
 using message_center::Notifier;
@@ -98,6 +98,7 @@ ProfileNotifierGroup::ProfileNotifierGroup(const gfx::Image& icon,
 }  // namespace message_center
 
 namespace {
+
 class NotifierComparator {
  public:
   explicit NotifierComparator(icu::Collator* collator) : collator_(collator) {}
@@ -117,6 +118,255 @@ class NotifierComparator {
   icu::Collator* collator_;
 };
 
+class ApplicationNotifiereSource : public NotifierSource,
+                                   public AppIconLoaderDelegate {
+ public:
+  explicit ApplicationNotifiereSource(
+       message_center::NotifierSettingsObserver* parent)
+      : NotifierSource(parent) {}
+
+  std::vector<std::unique_ptr<message_center::Notifier>> GetNotifierList(
+      Profile* profile) override {
+    std::vector<std::unique_ptr<message_center::Notifier>> notifiers;
+    NotifierStateTracker* const notifier_state_tracker =
+        NotifierStateTrackerFactory::GetForProfile(profile);
+    const extensions::ExtensionSet& extension_set =
+        extensions::ExtensionRegistry::Get(profile)->enabled_extensions();
+    // The extension icon size has to be 32x32 at least to load bigger icons if
+    // the icon doesn't exist for the specified size, and in that case it falls
+    // back to the default icon. The fetched icon will be resized in the
+    // settings dialog. See chrome/browser/extensions/extension_icon_image.cc
+    // and crbug.com/222931
+    app_icon_loader_.reset(new extensions::ExtensionAppIconLoader(
+        profile, extension_misc::EXTENSION_ICON_SMALL, this));
+    for (extensions::ExtensionSet::const_iterator iter = extension_set.begin();
+         iter != extension_set.end(); ++iter) {
+      const extensions::Extension* extension = iter->get();
+      if (!extension->permissions_data()->HasAPIPermission(
+              extensions::APIPermission::kNotifications)) {
+        continue;
+      }
+
+      // Hosted apps are no longer able to affect the notifications permission
+      // state for web notifications.
+      // TODO(dewittj): Deprecate the 'notifications' permission for hosted
+      // apps.
+      if (extension->is_hosted_app())
+        continue;
+
+      NotifierId notifier_id(NotifierId::APPLICATION, extension->id());
+      notifiers.emplace_back(
+          new Notifier(notifier_id, base::UTF8ToUTF16(extension->name()),
+                       notifier_state_tracker->IsNotifierEnabled(notifier_id)));
+      app_icon_loader_->FetchImage(extension->id());
+    }
+
+    return notifiers;
+  }
+
+  void SetNotifierEnabled(Profile* profile,
+                          const message_center::Notifier& notifier,
+                          bool enabled) override {
+    NotifierStateTrackerFactory::GetForProfile(profile)->SetNotifierEnabled(
+        notifier.notifier_id, enabled);
+    parent_->NotifierEnabledChanged(notifier.notifier_id, enabled);
+  }
+
+  message_center::NotifierId::NotifierType GetNotifierType() override {
+    return NotifierId::APPLICATION;
+  }
+
+ private:
+  // Overridden from AppIconLoaderDelegate.
+  void OnAppImageUpdated(const std::string& id,
+                         const gfx::ImageSkia& image) override {
+    parent_->UpdateIconImage(NotifierId(NotifierId::APPLICATION, id),
+                             gfx::Image(image));
+  }
+
+  std::unique_ptr<AppIconLoader> app_icon_loader_;
+};
+
+class WebPageNotifiereSource : public NotifierSource {
+ public:
+  explicit WebPageNotifiereSource(
+       message_center::NotifierSettingsObserver* parent)
+      : NotifierSource(parent) {}
+
+  std::vector<std::unique_ptr<message_center::Notifier>> GetNotifierList(
+      Profile* profile) override {
+    std::vector<std::unique_ptr<message_center::Notifier>> notifiers;
+    NotifierStateTracker* const notifier_state_tracker =
+        NotifierStateTrackerFactory::GetForProfile(profile);
+    ContentSettingsForOneType settings;
+    DesktopNotificationProfileUtil::GetNotificationsSettings(profile,
+                                                             &settings);
+
+    favicon::FaviconService* const favicon_service =
+        FaviconServiceFactory::GetForProfile(
+            profile, ServiceAccessType::EXPLICIT_ACCESS);
+    favicon_tracker_.reset(new base::CancelableTaskTracker());
+    patterns_.clear();
+    for (ContentSettingsForOneType::const_iterator iter = settings.begin();
+         iter != settings.end(); ++iter) {
+      if (iter->primary_pattern == ContentSettingsPattern::Wildcard() &&
+          iter->secondary_pattern == ContentSettingsPattern::Wildcard() &&
+          iter->source != "preference") {
+        continue;
+      }
+
+      std::string url_pattern = iter->primary_pattern.ToString();
+      base::string16 name = base::UTF8ToUTF16(url_pattern);
+      GURL url(url_pattern);
+      NotifierId notifier_id(url);
+      notifiers.emplace_back(
+          new Notifier(notifier_id, name,
+                       notifier_state_tracker->IsNotifierEnabled(notifier_id)));
+      patterns_[name] = iter->primary_pattern;
+      // Note that favicon service obtains the favicon from history. This means
+      // that it will fail to obtain the image if there are no history data for
+      // that URL.
+      favicon_service->GetFaviconImageForPageURL(
+          url, base::Bind(&WebPageNotifiereSource::OnFaviconLoaded,
+                          base::Unretained(this), url),
+          favicon_tracker_.get());
+    }
+
+    return notifiers;
+  }
+
+  void SetNotifierEnabled(Profile* profile,
+                          const message_center::Notifier& notifier,
+                          bool enabled) override {
+    // WEB_PAGE notifier cannot handle in DesktopNotificationService
+    // since it has the exact URL pattern.
+    // TODO(mukai): fix this.
+    ContentSetting default_setting =
+        HostContentSettingsMapFactory::GetForProfile(profile)
+            ->GetDefaultContentSetting(CONTENT_SETTINGS_TYPE_NOTIFICATIONS,
+                                       NULL);
+
+    DCHECK(default_setting == CONTENT_SETTING_ALLOW ||
+           default_setting == CONTENT_SETTING_BLOCK ||
+           default_setting == CONTENT_SETTING_ASK);
+
+    // The content setting for notifications needs to clear when it changes to
+    // the default value or get explicitly set when it differs from the
+    // default.
+    bool differs_from_default_value =
+        (default_setting != CONTENT_SETTING_ALLOW && enabled) ||
+        (default_setting == CONTENT_SETTING_ALLOW && !enabled);
+
+    if (differs_from_default_value) {
+      if (notifier.notifier_id.url.is_valid()) {
+        if (enabled) {
+          DesktopNotificationProfileUtil::GrantPermission(
+              profile, notifier.notifier_id.url);
+        } else {
+          DesktopNotificationProfileUtil::DenyPermission(
+              profile, notifier.notifier_id.url);
+        }
+      } else {
+        LOG(ERROR) << "Invalid url pattern: "
+                   << notifier.notifier_id.url.spec();
+      }
+    } else {
+      ContentSettingsPattern pattern;
+
+      const auto& iter = patterns_.find(notifier.name);
+      if (iter != patterns_.end()) {
+        pattern = iter->second;
+      } else if (notifier.notifier_id.url.is_valid()) {
+        pattern =
+            ContentSettingsPattern::FromURLNoWildcard(notifier.notifier_id.url);
+      } else {
+        LOG(ERROR) << "Invalid url pattern: "
+                   << notifier.notifier_id.url.spec();
+      }
+
+      if (pattern.IsValid()) {
+        // Note that we don't use
+        // DesktopNotificationProfileUtil::ClearSetting()
+        // here because pattern might be from user manual input and not match
+        // the default one used by ClearSetting().
+        HostContentSettingsMapFactory::GetForProfile(profile)
+            ->SetContentSettingCustomScope(
+                pattern, ContentSettingsPattern::Wildcard(),
+                CONTENT_SETTINGS_TYPE_NOTIFICATIONS,
+                content_settings::ResourceIdentifier(),
+                CONTENT_SETTING_DEFAULT);
+      }
+    }
+
+    parent_->NotifierEnabledChanged(notifier.notifier_id, enabled);
+  }
+
+  void OnNotifierSettingsClosing() override {
+    DCHECK(favicon_tracker_.get());
+    favicon_tracker_->TryCancelAll();
+    patterns_.clear();
+  }
+
+  message_center::NotifierId::NotifierType GetNotifierType() override {
+    return NotifierId::WEB_PAGE;
+  }
+
+ private:
+  void OnFaviconLoaded(const GURL& url,
+                       const favicon_base::FaviconImageResult& favicon_result) {
+    parent_->UpdateIconImage(NotifierId(url), favicon_result.image);
+  }
+
+  std::map<base::string16, ContentSettingsPattern> patterns_;
+
+  // The task tracker for loading favicons.
+  std::unique_ptr<base::CancelableTaskTracker> favicon_tracker_;
+};
+
+#if defined(OS_CHROMEOS)
+class SystemComponentNotifierSource : public NotifierSource {
+ public:
+  explicit SystemComponentNotifierSource(
+       message_center::NotifierSettingsObserver* parent)
+      : NotifierSource(parent) {}
+
+  std::vector<std::unique_ptr<message_center::Notifier>> GetNotifierList(
+      Profile* profile) override {
+    std::vector<std::unique_ptr<message_center::Notifier>> notifiers;
+    NotifierStateTracker* const notifier_state_tracker =
+        NotifierStateTrackerFactory::GetForProfile(profile);
+
+    // Screenshot notification feature is only for ChromeOS. See
+    // crbug.com/238358
+    const base::string16& screenshot_name =
+        l10n_util::GetStringUTF16(IDS_MESSAGE_CENTER_NOTIFIER_SCREENSHOT_NAME);
+    NotifierId screenshot_notifier_id(
+        NotifierId::SYSTEM_COMPONENT,
+        ash::system_notifier::kNotifierScreenshot);
+    Notifier* const screenshot_notifier = new Notifier(
+        screenshot_notifier_id, screenshot_name,
+        notifier_state_tracker->IsNotifierEnabled(screenshot_notifier_id));
+    screenshot_notifier->icon =
+        ui::ResourceBundle::GetSharedInstance().GetImageNamed(
+            IDR_SCREENSHOT_NOTIFICATION_ICON);
+    notifiers.emplace_back(screenshot_notifier);
+    return notifiers;
+  }
+
+  void SetNotifierEnabled(Profile* profile,
+                          const message_center::Notifier& notifier,
+                          bool enabled) override {
+    NotifierStateTrackerFactory::GetForProfile(profile)->SetNotifierEnabled(
+        notifier.notifier_id, enabled);
+    parent_->NotifierEnabledChanged(notifier.notifier_id, enabled);
+  }
+
+  message_center::NotifierId::NotifierType GetNotifierType() override {
+    return NotifierId::SYSTEM_COMPONENT;
+  }
+};
+#endif
+
 }  // namespace
 
 MessageCenterSettingsController::MessageCenterSettingsController(
@@ -139,13 +389,24 @@ MessageCenterSettingsController::MessageCenterSettingsController(
   profile_attributes_storage_.AddObserver(this);
   RebuildNotifierGroups(false);
 
+  sources_.insert(std::make_pair(
+      NotifierId::APPLICATION,
+      std::unique_ptr<NotifierSource>(new ApplicationNotifiereSource(this))));
+  sources_.insert(std::make_pair(
+      NotifierId::WEB_PAGE,
+      std::unique_ptr<NotifierSource>(new WebPageNotifiereSource(this))));
+
 #if defined(OS_CHROMEOS)
   // UserManager may not exist in some tests.
   if (user_manager::UserManager::IsInitialized())
     user_manager::UserManager::Get()->AddSessionStateObserver(this);
-  // Check if ARC is enabled.
-  if (arc::ArcBridgeService::Get())
-    arc_notifier_manager_.reset(new arc::ArcNotifierManager());
+  // FOr system components.
+  sources_.insert(std::make_pair(NotifierId::SYSTEM_COMPONENT,
+                                 std::unique_ptr<NotifierSource>(
+                                     new SystemComponentNotifierSource(this))));
+  sources_.insert(std::make_pair(
+      NotifierId::ARC_APPLICATION,
+      std::unique_ptr<NotifierSource>(new arc::ArcNotifierSource(this))));
 #endif
 }
 
@@ -195,9 +456,7 @@ void MessageCenterSettingsController::SwitchToNotifierGroup(size_t index) {
     return;
 
   current_notifier_group_ = index;
-  FOR_EACH_OBSERVER(message_center::NotifierSettingsObserver,
-                    observers_,
-                    NotifierGroupChanged());
+  NotifierGroupChanged();
 }
 
 void MessageCenterSettingsController::GetNotifierList(
@@ -209,101 +468,13 @@ void MessageCenterSettingsController::GetNotifierList(
   // the default profile is not loaded.
   Profile* profile = notifier_groups_[current_notifier_group_]->profile();
 
-  NotifierStateTracker* notifier_state_tracker =
-      NotifierStateTrackerFactory::GetForProfile(profile);
-
-  const extensions::ExtensionSet& extension_set =
-      extensions::ExtensionRegistry::Get(profile)->enabled_extensions();
-  // The extension icon size has to be 32x32 at least to load bigger icons if
-  // the icon doesn't exist for the specified size, and in that case it falls
-  // back to the default icon. The fetched icon will be resized in the settings
-  // dialog. See chrome/browser/extensions/extension_icon_image.cc and
-  // crbug.com/222931
-  app_icon_loader_.reset(new extensions::ExtensionAppIconLoader(
-      profile, extension_misc::EXTENSION_ICON_SMALL, this));
-  for (extensions::ExtensionSet::const_iterator iter = extension_set.begin();
-       iter != extension_set.end();
-       ++iter) {
-    const extensions::Extension* extension = iter->get();
-    if (!extension->permissions_data()->HasAPIPermission(
-            extensions::APIPermission::kNotifications)) {
-      continue;
-    }
-
-    // Hosted apps are no longer able to affect the notifications permission
-    // state for web notifications.
-    // TODO(dewittj): Deprecate the 'notifications' permission for hosted apps.
-    if (extension->is_hosted_app())
-      continue;
-
-    NotifierId notifier_id(NotifierId::APPLICATION, extension->id());
-    notifiers->push_back(new Notifier(
-        notifier_id,
-        base::UTF8ToUTF16(extension->name()),
-        notifier_state_tracker->IsNotifierEnabled(notifier_id)));
-    app_icon_loader_->FetchImage(extension->id());
-  }
-
-  ContentSettingsForOneType settings;
-  DesktopNotificationProfileUtil::GetNotificationsSettings(profile, &settings);
-
-  favicon::FaviconService* favicon_service =
-      FaviconServiceFactory::GetForProfile(profile,
-                                           ServiceAccessType::EXPLICIT_ACCESS);
-  favicon_tracker_.reset(new base::CancelableTaskTracker());
-  patterns_.clear();
-  for (ContentSettingsForOneType::const_iterator iter = settings.begin();
-       iter != settings.end(); ++iter) {
-    if (iter->primary_pattern == ContentSettingsPattern::Wildcard() &&
-        iter->secondary_pattern == ContentSettingsPattern::Wildcard() &&
-        iter->source != "preference") {
-      continue;
-    }
-
-    std::string url_pattern = iter->primary_pattern.ToString();
-    base::string16 name = base::UTF8ToUTF16(url_pattern);
-    GURL url(url_pattern);
-    NotifierId notifier_id(url);
-    notifiers->push_back(new Notifier(
-        notifier_id,
-        name,
-        notifier_state_tracker->IsNotifierEnabled(notifier_id)));
-    patterns_[name] = iter->primary_pattern;
-    // Note that favicon service obtains the favicon from history. This means
-    // that it will fail to obtain the image if there are no history data for
-    // that URL.
-    favicon_service->GetFaviconImageForPageURL(
-        url,
-        base::Bind(&MessageCenterSettingsController::OnFaviconLoaded,
-                   base::Unretained(this),
-                   url),
-        favicon_tracker_.get());
-  }
-
-#if defined(OS_CHROMEOS)
-  // Add ARC++ apps.
-  if (arc_notifier_manager_) {
-    auto list = arc_notifier_manager_->GetNotifiers(profile);
-    for (auto& notifier : list) {
+  for (auto& source : sources_) {
+    auto source_notifiers = source.second->GetNotifierList(profile);
+    for (auto& notifier : source_notifiers) {
       notifiers->push_back(notifier.release());
     }
   }
 
-  // Screenshot notification feature is only for ChromeOS. See crbug.com/238358
-  const base::string16& screenshot_name =
-      l10n_util::GetStringUTF16(IDS_MESSAGE_CENTER_NOTIFIER_SCREENSHOT_NAME);
-  NotifierId screenshot_notifier_id(
-      NotifierId::SYSTEM_COMPONENT, ash::system_notifier::kNotifierScreenshot);
-  Notifier* const screenshot_notifier = new Notifier(
-      screenshot_notifier_id,
-      screenshot_name,
-      notifier_state_tracker->IsNotifierEnabled(screenshot_notifier_id));
-  screenshot_notifier->icon =
-      ui::ResourceBundle::GetSharedInstance().GetImageNamed(
-          IDR_SCREENSHOT_NOTIFICATION_ICON);
-  notifiers->push_back(screenshot_notifier);
-#endif
-
   UErrorCode error = U_ZERO_ERROR;
   std::unique_ptr<icu::Collator> collator(icu::Collator::createInstance(error));
   std::unique_ptr<NotifierComparator> comparator(
@@ -318,96 +489,19 @@ void MessageCenterSettingsController::SetNotifierEnabled(
   DCHECK_LT(current_notifier_group_, notifier_groups_.size());
   Profile* profile = notifier_groups_[current_notifier_group_]->profile();
 
-  switch (notifier.notifier_id.type) {
-    case NotifierId::WEB_PAGE: {
-      // WEB_PAGE notifier cannot handle in DesktopNotificationService
-      // since it has the exact URL pattern.
-      // TODO(mukai): fix this.
-      ContentSetting default_setting =
-          HostContentSettingsMapFactory::GetForProfile(profile)
-              ->GetDefaultContentSetting(CONTENT_SETTINGS_TYPE_NOTIFICATIONS,
-                                         NULL);
-
-      DCHECK(default_setting == CONTENT_SETTING_ALLOW ||
-             default_setting == CONTENT_SETTING_BLOCK ||
-             default_setting == CONTENT_SETTING_ASK);
-
-      // The content setting for notifications needs to clear when it changes to
-      // the default value or get explicitly set when it differs from the
-      // default.
-      bool differs_from_default_value =
-          (default_setting != CONTENT_SETTING_ALLOW && enabled) ||
-          (default_setting == CONTENT_SETTING_ALLOW && !enabled);
-
-      if (differs_from_default_value) {
-        if (notifier.notifier_id.url.is_valid()) {
-          if (enabled) {
-            DesktopNotificationProfileUtil::GrantPermission(
-                profile, notifier.notifier_id.url);
-          } else {
-            DesktopNotificationProfileUtil::DenyPermission(
-                profile, notifier.notifier_id.url);
-          }
-        } else {
-          LOG(ERROR) << "Invalid url pattern: "
-                     << notifier.notifier_id.url.spec();
-        }
-      } else {
-        ContentSettingsPattern pattern;
-
-        const auto& iter = patterns_.find(notifier.name);
-        if (iter != patterns_.end()) {
-          pattern = iter->second;
-        } else if (notifier.notifier_id.url.is_valid()) {
-          pattern = ContentSettingsPattern::FromURLNoWildcard(
-              notifier.notifier_id.url);
-        } else {
-          LOG(ERROR) << "Invalid url pattern: "
-                     << notifier.notifier_id.url.spec();
-        }
-
-        if (pattern.IsValid()) {
-          // Note that we don't use
-          // DesktopNotificationProfileUtil::ClearSetting()
-          // here because pattern might be from user manual input and not match
-          // the default one used by ClearSetting().
-          HostContentSettingsMapFactory::GetForProfile(profile)
-              ->SetContentSettingCustomScope(
-                  pattern, ContentSettingsPattern::Wildcard(),
-                  CONTENT_SETTINGS_TYPE_NOTIFICATIONS,
-                  content_settings::ResourceIdentifier(),
-                  CONTENT_SETTING_DEFAULT);
-        }
-      }
-      break;
-    }
-    case NotifierId::APPLICATION:
-    case NotifierId::SYSTEM_COMPONENT: {
-      NotifierStateTrackerFactory::GetForProfile(profile)->SetNotifierEnabled(
-          notifier.notifier_id, enabled);
-      break;
-    }
-    case NotifierId::ARC_APPLICATION: {
-#if defined(OS_CHROMEOS)
-      if (arc_notifier_manager_) {
-        arc_notifier_manager_->SetNotifierEnabled(notifier.notifier_id.id,
-                                                  enabled);
-      }
-#else
-      NOTREACHED();
-#endif
-      break;
-    }
+  if (!sources_.count(notifier.notifier_id.type)) {
+    NOTREACHED();
+    return;
   }
-  FOR_EACH_OBSERVER(message_center::NotifierSettingsObserver,
-                    observers_,
-                    NotifierEnabledChanged(notifier.notifier_id, enabled));
+
+  sources_[notifier.notifier_id.type]->SetNotifierEnabled(profile, notifier,
+                                                          enabled);
 }
 
 void MessageCenterSettingsController::OnNotifierSettingsClosing() {
-  DCHECK(favicon_tracker_.get());
-  favicon_tracker_->TryCancelAll();
-  patterns_.clear();
+  for (auto& source : sources_) {
+    source.second->OnNotifierSettingsClosing();
+  }
 }
 
 bool MessageCenterSettingsController::NotifierHasAdvancedSettings(
@@ -453,15 +547,6 @@ void MessageCenterSettingsController::OnNotifierAdvancedSettingsRequested(
   event_router->DispatchEventToExtension(extension_id, std::move(event));
 }
 
-void MessageCenterSettingsController::OnFaviconLoaded(
-    const GURL& url,
-    const favicon_base::FaviconImageResult& favicon_result) {
-  FOR_EACH_OBSERVER(message_center::NotifierSettingsObserver,
-                    observers_,
-                    UpdateIconImage(NotifierId(url), favicon_result.image));
-}
-
-
 #if defined(OS_CHROMEOS)
 void MessageCenterSettingsController::ActiveUserChanged(
     const user_manager::User* active_user) {
@@ -469,14 +554,6 @@ void MessageCenterSettingsController::ActiveUserChanged(
 }
 #endif
 
-void MessageCenterSettingsController::OnAppImageUpdated(
-    const std::string& id, const gfx::ImageSkia& image) {
-  FOR_EACH_OBSERVER(message_center::NotifierSettingsObserver,
-                    observers_,
-                    UpdateIconImage(NotifierId(NotifierId::APPLICATION, id),
-                                    gfx::Image(image)));
-}
-
 void MessageCenterSettingsController::Observe(
     int type,
     const content::NotificationSource& source,
@@ -510,6 +587,25 @@ void MessageCenterSettingsController::OnProfileAuthInfoChanged(
   RebuildNotifierGroups(true);
 }
 
+void MessageCenterSettingsController::UpdateIconImage(
+    const message_center::NotifierId& id,
+    const gfx::Image& image) {
+  FOR_EACH_OBSERVER(message_center::NotifierSettingsObserver, observers_,
+                    UpdateIconImage(id, image));
+}
+
+void MessageCenterSettingsController::NotifierGroupChanged() {
+  FOR_EACH_OBSERVER(message_center::NotifierSettingsObserver, observers_,
+                    NotifierGroupChanged());
+}
+
+void MessageCenterSettingsController::NotifierEnabledChanged(
+    const message_center::NotifierId& id,
+    bool enabled) {
+  FOR_EACH_OBSERVER(message_center::NotifierSettingsObserver, observers_,
+                    NotifierEnabledChanged(id, enabled));
+}
+
 #if defined(OS_CHROMEOS)
 void MessageCenterSettingsController::CreateNotifierGroupForGuestLogin() {
   // Already created.
@@ -532,10 +628,7 @@ void MessageCenterSettingsController::CreateNotifierGroupForGuestLogin() {
           user->GetDisplayName(), profile));
 
   notifier_groups_.push_back(std::move(group));
-
-  FOR_EACH_OBSERVER(message_center::NotifierSettingsObserver,
-                    observers_,
-                    NotifierGroupChanged());
+  NotifierGroupChanged();
 }
 #endif
 
@@ -595,9 +688,6 @@ void MessageCenterSettingsController::RebuildNotifierGroups(bool notify) {
   }
 #endif
 
-  if (notify) {
-    FOR_EACH_OBSERVER(message_center::NotifierSettingsObserver,
-                      observers_,
-                      NotifierGroupChanged());
-  }
+  if (notify)
+    NotifierGroupChanged();
 }