Add SystemTrayObservers

Once there is more than one SystemTray instance, we will need to support observer lists so that multiple tray items can be notified.

Hosting the observer lists in a separate class owned by ass::SystemTrayDelegate seemed like the most forward approach.

BUG=159543
For ash.gyp:
TBR=sky@chromium.org


Review URL: https://chromiumcodereview.appspot.com/11312139

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@167548 0039d316-1c4b-4281-b951-d872f2087c98

13 files changed, 474 insertions, 243 deletions

diff --git a/ash/ash.gyp b/ash/ash.gyp
index 649062c4..ac60ac8 100644
--- a/ash/ash.gyp
+++ b/ash/ash.gyp
@@ -213,6 +213,8 @@
         'system/tray/system_tray_delegate.h',
         'system/tray/system_tray_item.cc',
         'system/tray/system_tray_item.h',
+        'system/tray/system_tray_notifier.cc',
+        'system/tray/system_tray_notifier.h',
         'system/tray/test_system_tray_delegate.cc',
         'system/tray/test_system_tray_delegate.h',
         'system/tray/tray_background_view.cc',
diff --git a/ash/shell.cc b/ash/shell.cc
index bac0bb6..45dc886 100644
--- a/ash/shell.cc
+++ b/ash/shell.cc
@@ -29,6 +29,7 @@
 #include "ash/shell_window_ids.h"
 #include "ash/system/status_area_widget.h"
 #include "ash/system/tray/system_tray_delegate.h"
+#include "ash/system/tray/system_tray_notifier.h"
 #include "ash/tooltips/tooltip_controller.h"
 #include "ash/touch/touch_observer_hud.h"
 #include "ash/wm/activation_controller.h"
@@ -257,6 +258,11 @@ Shell::~Shell() {
   // Destroy SystemTrayDelegate before destroying the status area(s).
   system_tray_delegate_.reset();
 
+  // Destroy SystemTrayNotifier immediately after destroying SystemTrayDelegate
+  // so that it is still available when shutting down the UI, but not after
+  // the notifier observers have been destroyed.
+  system_tray_notifier_.reset();
+
   // Destroy all child windows including widgets.
   display_controller_->CloseChildWindows();
 
@@ -495,6 +501,9 @@ void Shell::Init() {
     shadow_controller_.reset(new internal::ShadowController());
   }
 
+  // Create system_tray_notifier_ before the delegate.
+  system_tray_notifier_.reset(new ash::SystemTrayNotifier());
+
   // Initialize system_tray_delegate_ before initializing StatusAreaWidget.
   system_tray_delegate_.reset(delegate()->CreateSystemTrayDelegate());
   if (!system_tray_delegate_.get())
diff --git a/ash/shell.h b/ash/shell.h
index 8e27380..72073dc 100644
--- a/ash/shell.h
+++ b/ash/shell.h
@@ -75,6 +75,7 @@ class ShellDelegate;
 class ShellObserver;
 class SystemTray;
 class SystemTrayDelegate;
+class SystemTrayNotifier;
 class UserActivityDetector;
 class UserWallpaperDelegate;
 class VideoDetector;
@@ -372,6 +373,10 @@ class ASH_EXPORT Shell : internal::SystemModalContainerEventFilterDelegate,
     return system_tray_delegate_.get();
   }
 
+  SystemTrayNotifier* system_tray_notifier() {
+    return system_tray_notifier_.get();
+  }
+
   static void set_initially_hide_cursor(bool hide) {
     initially_hide_cursor_ = hide;
   }
@@ -460,6 +465,7 @@ class ASH_EXPORT Shell : internal::SystemModalContainerEventFilterDelegate,
 
   scoped_ptr<ShellDelegate> delegate_;
   scoped_ptr<SystemTrayDelegate> system_tray_delegate_;
+  scoped_ptr<SystemTrayNotifier> system_tray_notifier_;
   scoped_ptr<UserWallpaperDelegate> user_wallpaper_delegate_;
   scoped_ptr<CapsLockDelegate> caps_lock_delegate_;
 
diff --git a/ash/system/status_area_widget.cc b/ash/system/status_area_widget.cc
index b487de5..c1b165f 100644
--- a/ash/system/status_area_widget.cc
+++ b/ash/system/status_area_widget.cc
@@ -46,13 +46,14 @@ StatusAreaWidget::~StatusAreaWidget() {
 void StatusAreaWidget::CreateTrayViews() {
   AddSystemTray();
   AddWebNotificationTray();
-  // Initialize() must be called after all trays have been created.
+  SystemTrayDelegate* delegate = ash::Shell::GetInstance()->tray_delegate();
+  DCHECK(delegate);
+  // Initialize after all trays have been created.
   if (system_tray_)
-    system_tray_->Initialize();
+    system_tray_->InitializeTrayItems(delegate);
   if (web_notification_tray_)
     web_notification_tray_->Initialize();
-  UpdateAfterLoginStatusChange(
-      ash::Shell::GetInstance()->tray_delegate()->GetUserLoginStatus());
+  UpdateAfterLoginStatusChange(delegate->GetUserLoginStatus());
 }
 
 void StatusAreaWidget::Shutdown() {
diff --git a/ash/system/tray/system_tray.cc b/ash/system/tray/system_tray.cc
index e7d8385..9ba7800 100644
--- a/ash/system/tray/system_tray.cc
+++ b/ash/system/tray/system_tray.cc
@@ -18,12 +18,12 @@
 #include "ash/system/locale/tray_locale.h"
 #include "ash/system/logout_button/tray_logout_button.h"
 #include "ash/system/monitor/tray_monitor.h"
-#include "ash/system/power/power_status_observer.h"
 #include "ash/system/power/power_supply_status.h"
 #include "ash/system/power/tray_power.h"
 #include "ash/system/settings/tray_settings.h"
 #include "ash/system/status_area_widget.h"
 #include "ash/system/tray/system_tray_delegate.h"
+#include "ash/system/tray/system_tray_notifier.h"
 #include "ash/system/tray/system_tray_item.h"
 #include "ash/system/tray/tray_bubble_wrapper.h"
 #include "ash/system/tray/tray_constants.h"
@@ -107,23 +107,6 @@ using internal::SystemTrayBubble;
 SystemTray::SystemTray(internal::StatusAreaWidget* status_area_widget)
     : internal::TrayBackgroundView(status_area_widget),
       items_(),
-      accessibility_observer_(NULL),
-      audio_observer_(NULL),
-      bluetooth_observer_(NULL),
-      brightness_observer_(NULL),
-      caps_lock_observer_(NULL),
-      clock_observer_(NULL),
-      drive_observer_(NULL),
-      ime_observer_(NULL),
-      locale_observer_(NULL),
-      logout_button_observer_(NULL),
-#if defined(OS_CHROMEOS)
-      network_observer_(NULL),
-      vpn_observer_(NULL),
-      sms_observer_(NULL),
-#endif
-      update_observer_(NULL),
-      user_observer_(NULL),
       default_bubble_height_(0),
       hide_notifications_(false) {
   SetContentsBackground();
@@ -140,47 +123,54 @@ SystemTray::~SystemTray() {
   }
 }
 
-void SystemTray::CreateItems() {
+void SystemTray::InitializeTrayItems(SystemTrayDelegate* delegate) {
+  internal::TrayBackgroundView::Initialize();
+  CreateItems(delegate);
+}
+
+void SystemTray::CreateItems(SystemTrayDelegate* delegate) {
   internal::TrayVolume* tray_volume = new internal::TrayVolume();
   internal::TrayBluetooth* tray_bluetooth = new internal::TrayBluetooth();
   internal::TrayBrightness* tray_brightness = new internal::TrayBrightness();
   internal::TrayDate* tray_date = new internal::TrayDate();
   internal::TrayPower* tray_power = new internal::TrayPower();
-  internal::TrayIME* tray_ime = new internal::TrayIME;
-  internal::TrayUser* tray_user = new internal::TrayUser;
+  internal::TrayIME* tray_ime = new internal::TrayIME();
+  internal::TrayUser* tray_user = new internal::TrayUser();
   internal::TrayAccessibility* tray_accessibility =
-      new internal::TrayAccessibility;
-  internal::TrayCapsLock* tray_caps_lock = new internal::TrayCapsLock;
-  internal::TrayDrive* tray_drive = new internal::TrayDrive;
-  internal::TrayLocale* tray_locale = new internal::TrayLocale;
+      new internal::TrayAccessibility();
+  internal::TrayCapsLock* tray_caps_lock = new internal::TrayCapsLock();
+  internal::TrayDrive* tray_drive = new internal::TrayDrive();
+  internal::TrayLocale* tray_locale = new internal::TrayLocale();
   internal::TrayLogoutButton* tray_logout_button =
       new internal::TrayLogoutButton();
-  internal::TrayUpdate* tray_update = new internal::TrayUpdate;
+  internal::TrayUpdate* tray_update = new internal::TrayUpdate();
   internal::TraySettings* tray_settings = new internal::TraySettings();
-
-  accessibility_observer_ = tray_accessibility;
-  audio_observer_ = tray_volume;
-  bluetooth_observer_ = tray_bluetooth;
-  brightness_observer_ = tray_brightness;
-  caps_lock_observer_ = tray_caps_lock;
-  clock_observer_ = tray_date;
-  drive_observer_ = tray_drive;
-  ime_observer_ = tray_ime;
-  locale_observer_ = tray_locale;
-  logout_button_observer_ = tray_logout_button;
-  power_status_observers_.AddObserver(tray_power);
-  power_status_observers_.AddObserver(tray_settings);
-  update_observer_ = tray_update;
-  user_observer_ = tray_user;
-
 #if defined(OS_CHROMEOS)
-  internal::TrayDisplay* tray_display = new internal::TrayDisplay;
-  internal::TrayNetwork* tray_network = new internal::TrayNetwork;
-  internal::TrayVPN* tray_vpn = new internal::TrayVPN;
+  internal::TrayDisplay* tray_display = new internal::TrayDisplay();
+  internal::TrayNetwork* tray_network = new internal::TrayNetwork();
+  internal::TrayVPN* tray_vpn = new internal::TrayVPN();
   internal::TraySms* tray_sms = new internal::TraySms();
-  network_observer_ = tray_network;
-  vpn_observer_ = tray_vpn;
-  sms_observer_ = tray_sms;
+#endif
+
+  SystemTrayNotifier* notifier = Shell::GetInstance()->system_tray_notifier();
+  notifier->AddAccessibilityObserver(tray_accessibility);
+  notifier->AddAudioObserver(tray_volume);
+  notifier->AddBluetoothObserver(tray_bluetooth);
+  notifier->AddBrightnessObserver(tray_brightness);
+  notifier->AddCapsLockObserver(tray_caps_lock);
+  notifier->AddClockObserver(tray_date);
+  notifier->AddDriveObserver(tray_drive);
+  notifier->AddIMEObserver(tray_ime);
+  notifier->AddLocaleObserver(tray_locale);
+  notifier->AddLogoutButtonObserver(tray_logout_button);
+  notifier->AddPowerStatusObserver(tray_power);
+  notifier->AddPowerStatusObserver(tray_settings);
+  notifier->AddUpdateObserver(tray_update);
+  notifier->AddUserObserver(tray_user);
+#if defined(OS_CHROMEOS)
+  notifier->AddNetworkObserver(tray_network);
+  notifier->AddVpnObserver(tray_vpn);
+  notifier->AddSmsObserver(tray_sms);
 #endif
 
   AddTrayItem(tray_logout_button);
@@ -498,11 +488,6 @@ void SystemTray::UpdateNotificationBubble() {
     status_area_widget()->SetHideWebNotifications(true);
 }
 
-void SystemTray::Initialize() {
-  internal::TrayBackgroundView::Initialize();
-  CreateItems();
-}
-
 void SystemTray::SetShelfAlignment(ShelfAlignment alignment) {
   if (alignment == shelf_alignment())
     return;
diff --git a/ash/system/tray/system_tray.h b/ash/system/tray/system_tray.h
index a42632f..57cc2e7 100644
--- a/ash/system/tray/system_tray.h
+++ b/ash/system/tray/system_tray.h
@@ -34,6 +34,7 @@ class IMEObserver;
 class LocaleObserver;
 class LogoutButtonObserver;
 class PowerStatusObserver;
+class SystemTrayDelegate;
 class UpdateObserver;
 class UserObserver;
 #if defined(OS_CHROMEOS)
@@ -61,8 +62,9 @@ class ASH_EXPORT SystemTray : public internal::TrayBackgroundView,
   explicit SystemTray(internal::StatusAreaWidget* status_area_widget);
   virtual ~SystemTray();
 
-  // Creates the default set of items for the sytem tray.
-  void CreateItems();
+  // Calls TrayBackgroundView::Initialize(), creates the tray items, and
+  // adds them to SystemTrayNotifier.
+  void InitializeTrayItems(SystemTrayDelegate* delegate);
 
   // Adds a new item in the tray.
   void AddTrayItem(SystemTrayItem* item);
@@ -118,64 +120,12 @@ class ASH_EXPORT SystemTray : public internal::TrayBackgroundView,
   // Returns true if the mouse is inside the notification bubble.
   bool IsMouseInNotificationBubble() const;
 
-  AccessibilityObserver* accessibility_observer() {
-    return accessibility_observer_;
-  }
-  AudioObserver* audio_observer() {
-    return audio_observer_;
-  }
-  BluetoothObserver* bluetooth_observer() {
-    return bluetooth_observer_;
-  }
-  BrightnessObserver* brightness_observer() {
-    return brightness_observer_;
-  }
-  CapsLockObserver* caps_lock_observer() {
-    return caps_lock_observer_;
-  }
-  ClockObserver* clock_observer() {
-    return clock_observer_;
-  }
-  DriveObserver* drive_observer() {
-    return drive_observer_;
-  }
-  IMEObserver* ime_observer() {
-    return ime_observer_;
-  }
-  LocaleObserver* locale_observer() {
-    return locale_observer_;
-  }
-  LogoutButtonObserver* logout_button_observer() {
-    return logout_button_observer_;
-  }
-#if defined(OS_CHROMEOS)
-  NetworkObserver* network_observer() {
-    return network_observer_;
-  }
-  NetworkObserver* vpn_observer() {
-    return vpn_observer_;
-  }
-  SmsObserver* sms_observer() {
-    return sms_observer_;
-  }
-#endif
-  ObserverList<PowerStatusObserver>& power_status_observers() {
-    return power_status_observers_;
-  }
-  UpdateObserver* update_observer() {
-    return update_observer_;
-  }
-  UserObserver* user_observer() {
-    return user_observer_;
-  }
-
   // Accessors for testing.
 
   // Returns true if the bubble exists.
   bool CloseBubbleForTest() const;
 
   // Overridden from TrayBackgroundView.
-  virtual void Initialize() OVERRIDE;
   virtual void SetShelfAlignment(ShelfAlignment alignment) OVERRIDE;
   virtual void AnchorUpdated() OVERRIDE;
   virtual string16 GetAccessibleNameForTray() OVERRIDE;
@@ -194,6 +144,9 @@ class ASH_EXPORT SystemTray : public internal::TrayBackgroundView,
   virtual void HideBubble(const views::TrayBubbleView* bubble_view) OVERRIDE;
 
  private:
+  // Creates the default set of items for the sytem tray.
+  void CreateItems(SystemTrayDelegate* delegate);
+
   // Returns true if the system_bubble_ exists and is of type |type|.
   bool HasSystemBubbleType(internal::SystemTrayBubble::BubbleType type);
 
@@ -237,26 +190,6 @@ class ASH_EXPORT SystemTray : public internal::TrayBackgroundView,
   // Mappings of system tray item and it's view in the tray.
   std::map<SystemTrayItem*, views::View*> tray_item_map_;
 
-  // These observers are not owned by the tray.
-  AccessibilityObserver* accessibility_observer_;
-  AudioObserver* audio_observer_;
-  BluetoothObserver* bluetooth_observer_;
-  BrightnessObserver* brightness_observer_;
-  CapsLockObserver* caps_lock_observer_;
-  ClockObserver* clock_observer_;
-  DriveObserver* drive_observer_;
-  IMEObserver* ime_observer_;
-  LocaleObserver* locale_observer_;
-  LogoutButtonObserver* logout_button_observer_;
-#if defined(OS_CHROMEOS)
-  NetworkObserver* network_observer_;
-  NetworkObserver* vpn_observer_;
-  SmsObserver* sms_observer_;
-#endif
-  ObserverList<PowerStatusObserver> power_status_observers_;
-  UpdateObserver* update_observer_;
-  UserObserver* user_observer_;
-
   // Bubble for default and detailed views.
   scoped_ptr<internal::SystemBubbleWrapper> system_bubble_;
 
diff --git a/ash/system/tray/system_tray_notifier.cc b/ash/system/tray/system_tray_notifier.cc
new file mode 100644
index 0000000..66d490d
--- /dev/null
+++ b/ash/system/tray/system_tray_notifier.cc
@@ -0,0 +1,237 @@
+// Copyright (c) 2012 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 "ash/system/tray/system_tray_notifier.h"
+
+namespace ash {
+
+SystemTrayNotifier::SystemTrayNotifier() {
+}
+
+SystemTrayNotifier::~SystemTrayNotifier() {
+}
+
+void SystemTrayNotifier::AddAccessibilityObserver(
+    AccessibilityObserver* observer) {
+  accessibility_observers_.AddObserver(observer);
+}
+
+void SystemTrayNotifier::AddAudioObserver(AudioObserver* observer) {
+  audio_observers_.AddObserver(observer);
+}
+
+void SystemTrayNotifier::AddBluetoothObserver(BluetoothObserver* observer) {
+  bluetooth_observers_.AddObserver(observer);
+}
+
+void SystemTrayNotifier::AddBrightnessObserver(BrightnessObserver* observer) {
+  brightness_observers_.AddObserver(observer);
+}
+
+void SystemTrayNotifier::AddCapsLockObserver(CapsLockObserver* observer) {
+  caps_lock_observers_.AddObserver(observer);
+}
+
+void SystemTrayNotifier::AddClockObserver(ClockObserver* observer) {
+  clock_observers_.AddObserver(observer);
+}
+
+void SystemTrayNotifier::AddDriveObserver(DriveObserver* observer) {
+  drive_observers_.AddObserver(observer);
+}
+
+void SystemTrayNotifier::AddIMEObserver(IMEObserver* observer) {
+  ime_observers_.AddObserver(observer);
+}
+
+void SystemTrayNotifier::AddLocaleObserver(LocaleObserver* observer) {
+  locale_observers_.AddObserver(observer);
+}
+
+void SystemTrayNotifier::AddLogoutButtonObserver(
+    LogoutButtonObserver* observer) {
+  logout_button_observers_.AddObserver(observer);
+}
+
+void SystemTrayNotifier::AddPowerStatusObserver(
+    PowerStatusObserver* observer) {
+  power_status_observers_.AddObserver(observer);
+}
+
+void SystemTrayNotifier::AddUpdateObserver(UpdateObserver* observer) {
+  update_observers_.AddObserver(observer);
+}
+
+void SystemTrayNotifier::AddUserObserver(UserObserver* observer) {
+  user_observers_.AddObserver(observer);
+}
+
+#if defined(OS_CHROMEOS)
+void SystemTrayNotifier::AddNetworkObserver(NetworkObserver* observer) {
+  network_observers_.AddObserver(observer);
+}
+
+void SystemTrayNotifier::AddVpnObserver(NetworkObserver* observer) {
+  vpn_observers_.AddObserver(observer);
+}
+
+void SystemTrayNotifier::AddSmsObserver(SmsObserver* observer) {
+  sms_observers_.AddObserver(observer);
+}
+#endif
+
+void SystemTrayNotifier::NotifyAccessibilityModeChanged(
+    bool spoken_feedback_enabled) {
+  FOR_EACH_OBSERVER(
+      AccessibilityObserver,
+      accessibility_observers_,
+      OnAccessibilityModeChanged(spoken_feedback_enabled));
+}
+
+void SystemTrayNotifier::NotifyVolumeChanged(float level) {
+  FOR_EACH_OBSERVER(AudioObserver,
+                    audio_observers_,
+                    OnVolumeChanged(level));
+}
+
+void SystemTrayNotifier::NotifyMuteToggled() {
+  FOR_EACH_OBSERVER(AudioObserver,
+                    audio_observers_,
+                    OnMuteToggled());
+}
+
+void SystemTrayNotifier::NotifyRefreshBluetooth() {
+  FOR_EACH_OBSERVER(BluetoothObserver,
+                    bluetooth_observers_,
+                    OnBluetoothRefresh());
+}
+
+void SystemTrayNotifier::NotifyBluetoothDiscoveringChanged() {
+  FOR_EACH_OBSERVER(BluetoothObserver,
+                    bluetooth_observers_,
+                    OnBluetoothDiscoveringChanged());
+}
+
+void SystemTrayNotifier::NotifyBrightnessChanged(double level,
+                                                 bool user_initiated) {
+  FOR_EACH_OBSERVER(
+      BrightnessObserver,
+      brightness_observers_,
+      OnBrightnessChanged(level, user_initiated));
+}
+
+void SystemTrayNotifier::NotifyCapsLockChanged(
+    bool enabled,
+    bool search_mapped_to_caps_lock) {
+  FOR_EACH_OBSERVER(CapsLockObserver,
+                    caps_lock_observers_,
+                    OnCapsLockChanged(enabled, search_mapped_to_caps_lock));
+}
+
+void SystemTrayNotifier::NotifyRefreshClock() {
+  FOR_EACH_OBSERVER(ClockObserver, clock_observers_, Refresh());
+}
+
+void SystemTrayNotifier::NotifyDateFormatChanged() {
+  FOR_EACH_OBSERVER(ClockObserver,
+                    clock_observers_,
+                    OnDateFormatChanged());
+}
+
+void SystemTrayNotifier::NotifyRefreshDrive(DriveOperationStatusList& list) {
+  FOR_EACH_OBSERVER(DriveObserver,
+                    drive_observers_,
+                    OnDriveRefresh(list));
+}
+
+void SystemTrayNotifier::NotifyRefreshIME(bool show_message) {
+  FOR_EACH_OBSERVER(IMEObserver,
+                    ime_observers_,
+                    OnIMERefresh(show_message));
+}
+
+void SystemTrayNotifier::NotifyShowLoginButtonChanged(bool show_login_button) {
+  FOR_EACH_OBSERVER(LogoutButtonObserver,
+                    logout_button_observers_,
+                    OnShowLogoutButtonInTrayChanged(show_login_button));
+}
+
+void SystemTrayNotifier::NotifyLocaleChanged(
+    LocaleObserver::Delegate* delegate,
+    const std::string& cur_locale,
+    const std::string& from_locale,
+    const std::string& to_locale) {
+  FOR_EACH_OBSERVER(
+      LocaleObserver,
+      locale_observers_,
+      OnLocaleChanged(delegate, cur_locale, from_locale, to_locale));
+}
+
+void SystemTrayNotifier::NotifyPowerStatusChanged(
+    const PowerSupplyStatus& power_status) {
+  FOR_EACH_OBSERVER(PowerStatusObserver,
+                    power_status_observers_,
+                    OnPowerStatusChanged(power_status));
+}
+
+void SystemTrayNotifier::NotifyUpdateRecommended(
+    UpdateObserver::UpdateSeverity severity) {
+  FOR_EACH_OBSERVER(UpdateObserver,
+                    update_observers_,
+                    OnUpdateRecommended(severity));
+}
+
+void SystemTrayNotifier::NotifyUserUpdate() {
+  FOR_EACH_OBSERVER(UserObserver,
+                    user_observers_,
+                    OnUserUpdate());
+}
+
+#if defined(OS_CHROMEOS)
+
+void SystemTrayNotifier::NotifyRefreshNetwork(const NetworkIconInfo &info) {
+  FOR_EACH_OBSERVER(NetworkObserver,
+                    network_observers_,
+                    OnNetworkRefresh(info));
+}
+
+void SystemTrayNotifier::NotifySetNetworkMessage(
+    NetworkTrayDelegate* delegate,
+    NetworkObserver::MessageType message_type,
+    const string16& title,
+    const string16& message,
+    const std::vector<string16>& links) {
+  FOR_EACH_OBSERVER(NetworkObserver,
+                    network_observers_,
+                    SetNetworkMessage(
+                        delegate, message_type, title, message, links));
+}
+
+void SystemTrayNotifier::NotifyClearNetworkMessage(
+    NetworkObserver::MessageType message_type) {
+  FOR_EACH_OBSERVER(NetworkObserver,
+                    network_observers_,
+                    ClearNetworkMessage(message_type));
+}
+
+void SystemTrayNotifier::NotifyVpnRefreshNetwork(const NetworkIconInfo &info) {
+  FOR_EACH_OBSERVER(NetworkObserver,
+                    vpn_observers_,
+                    OnNetworkRefresh(info));
+}
+
+void SystemTrayNotifier::NotifyWillToggleWifi() {
+  FOR_EACH_OBSERVER(NetworkObserver,
+                    network_observers_,
+                    OnWillToggleWifi());
+}
+
+void SystemTrayNotifier::NotifyAddSmsMessage(
+    const base::DictionaryValue& message) {
+  FOR_EACH_OBSERVER(SmsObserver, sms_observers_, AddMessage(message));
+}
+
+#endif  // OS_CHROMEOS
+
+}  // namespace ash
diff --git a/ash/system/tray/system_tray_notifier.h b/ash/system/tray/system_tray_notifier.h
new file mode 100644
index 0000000..b755167
--- /dev/null
+++ b/ash/system/tray/system_tray_notifier.h
@@ -0,0 +1,117 @@
+// Copyright (c) 2012 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.
+
+#ifndef ASH_SYSTEM_TRAY_SYSTEM_TRAY_NOTIFIER_H_
+#define ASH_SYSTEM_TRAY_SYSTEM_TRAY_NOTIFIER_H_
+
+#include <string>
+#include <vector>
+
+#include "ash/ash_export.h"
+#include "ash/system/audio/audio_observer.h"
+#include "ash/system/bluetooth/bluetooth_observer.h"
+#include "ash/system/brightness/brightness_observer.h"
+#include "ash/system/chromeos/network/network_observer.h"
+#include "ash/system/chromeos/network/sms_observer.h"
+#include "ash/system/date/clock_observer.h"
+#include "ash/system/drive/drive_observer.h"
+#include "ash/system/ime/ime_observer.h"
+#include "ash/system/locale/locale_observer.h"
+#include "ash/system/logout_button/logout_button_observer.h"
+#include "ash/system/power/power_status_observer.h"
+#include "ash/system/tray_accessibility.h"
+#include "ash/system/tray_caps_lock.h"
+#include "ash/system/user/update_observer.h"
+#include "ash/system/user/user_observer.h"
+#include "base/observer_list.h"
+
+#if defined(OS_CHROMEOS)
+#include "ash/system/chromeos/network/network_observer.h"
+#include "ash/system/chromeos/network/sms_observer.h"
+#endif
+
+namespace ash {
+
+class ASH_EXPORT SystemTrayNotifier {
+public:
+  SystemTrayNotifier();
+  ~SystemTrayNotifier();
+
+  void AddAccessibilityObserver(AccessibilityObserver* observer);
+  void AddAudioObserver(AudioObserver* observer);
+  void AddBluetoothObserver(BluetoothObserver* observer);
+  void AddBrightnessObserver(BrightnessObserver* observer);
+  void AddCapsLockObserver(CapsLockObserver* observer);
+  void AddClockObserver(ClockObserver* observer);
+  void AddDriveObserver(DriveObserver* observer);
+  void AddIMEObserver(IMEObserver* observer);
+  void AddLocaleObserver(LocaleObserver* observer);
+  void AddLogoutButtonObserver(LogoutButtonObserver* observer);
+  void AddPowerStatusObserver(PowerStatusObserver* observer);
+  void AddUpdateObserver(UpdateObserver* observer);
+  void AddUserObserver(UserObserver* observer);
+#if defined(OS_CHROMEOS)
+  void AddNetworkObserver(NetworkObserver* observer);
+  void AddVpnObserver(NetworkObserver* observer);
+  void AddSmsObserver(SmsObserver* observer);
+#endif
+
+  void NotifyAccessibilityModeChanged(bool spoken_feedback_enabled);
+  void NotifyVolumeChanged(float level);
+  void NotifyMuteToggled();
+  void NotifyRefreshBluetooth();
+  void NotifyBluetoothDiscoveringChanged();
+  void NotifyBrightnessChanged(double level, bool user_initialted);
+  void NotifyCapsLockChanged(bool enabled, bool search_mapped_to_caps_lock);
+  void NotifyRefreshClock();
+  void NotifyDateFormatChanged();
+  void NotifyRefreshDrive(DriveOperationStatusList& list);
+  void NotifyRefreshIME(bool show_message);
+  void NotifyShowLoginButtonChanged(bool show_login_button);
+  void NotifyLocaleChanged(LocaleObserver::Delegate* delegate,
+                           const std::string& cur_locale,
+                           const std::string& from_locale,
+                           const std::string& to_locale);
+  void NotifyPowerStatusChanged(const PowerSupplyStatus& power_status);
+  void NotifyUpdateRecommended(UpdateObserver::UpdateSeverity severity);
+  void NotifyUserUpdate();
+#if defined(OS_CHROMEOS)
+  void NotifyRefreshNetwork(const NetworkIconInfo &info);
+  void NotifySetNetworkMessage(NetworkTrayDelegate* delegate,
+                               NetworkObserver::MessageType message_type,
+                               const string16& title,
+                               const string16& message,
+                               const std::vector<string16>& links);
+  void NotifyClearNetworkMessage(NetworkObserver::MessageType message_type);
+  void NotifyVpnRefreshNetwork(const NetworkIconInfo &info);
+  void NotifyWillToggleWifi();
+  void NotifyAddSmsMessage(const base::DictionaryValue& message);
+#endif
+
+ private:
+  ObserverList<AccessibilityObserver> accessibility_observers_;
+  ObserverList<AudioObserver> audio_observers_;
+  ObserverList<BluetoothObserver> bluetooth_observers_;
+  ObserverList<BrightnessObserver> brightness_observers_;
+  ObserverList<CapsLockObserver> caps_lock_observers_;
+  ObserverList<ClockObserver> clock_observers_;
+  ObserverList<DriveObserver> drive_observers_;
+  ObserverList<IMEObserver> ime_observers_;
+  ObserverList<LocaleObserver> locale_observers_;
+  ObserverList<LogoutButtonObserver> logout_button_observers_;
+  ObserverList<PowerStatusObserver> power_status_observers_;
+  ObserverList<UpdateObserver> update_observers_;
+  ObserverList<UserObserver> user_observers_;
+#if defined(OS_CHROMEOS)
+  ObserverList<NetworkObserver> network_observers_;
+  ObserverList<NetworkObserver> vpn_observers_;
+  ObserverList<SmsObserver> sms_observers_;
+#endif
+
+  DISALLOW_COPY_AND_ASSIGN(SystemTrayNotifier);
+};
+
+}  // namespace ash
+
+#endif  // ASH_SYSTEM_TRAY_SYSTEM_TRAY_NOTIFIER_H_
diff --git a/chrome/browser/chromeos/locale_change_guard.cc b/chrome/browser/chromeos/locale_change_guard.cc
index 606bfb4..80108ab 100644
--- a/chrome/browser/chromeos/locale_change_guard.cc
+++ b/chrome/browser/chromeos/locale_change_guard.cc
@@ -6,6 +6,7 @@
 
 #include "ash/shell.h"
 #include "ash/system/tray/system_tray.h"
+#include "ash/system/tray/system_tray_notifier.h"
 #include "base/bind.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/app/chrome_command_ids.h"
@@ -171,10 +172,8 @@ void LocaleChangeGuard::Check() {
     PrepareChangingLocale(from_locale, to_locale);
   }
 
-  if (ash::Shell::GetInstance()->status_area_widget()) {
-    ash::Shell::GetInstance()->system_tray()->locale_observer()->
-        OnLocaleChanged(this, cur_locale, from_locale_, to_locale_);
-  }
+  ash::Shell::GetInstance()->system_tray_notifier()->NotifyLocaleChanged(
+      this, cur_locale, from_locale_, to_locale_);
 }
 
 void LocaleChangeGuard::AcceptLocaleChange() {
diff --git a/chrome/browser/chromeos/network_message_observer.cc b/chrome/browser/chromeos/network_message_observer.cc
index 5e24899..5501d76 100644
--- a/chrome/browser/chromeos/network_message_observer.cc
+++ b/chrome/browser/chromeos/network_message_observer.cc
@@ -8,6 +8,7 @@
 #include "ash/shell_delegate.h"
 #include "ash/system/chromeos/network/network_observer.h"
 #include "ash/system/tray/system_tray.h"
+#include "ash/system/tray/system_tray_notifier.h"
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/stl_util.h"
@@ -71,8 +72,8 @@ class NetworkMessageNotification : public ash::NetworkTrayDelegate {
   }
 
   void Hide() {
-    ash::Shell::GetInstance()->system_tray()->network_observer()->
-        ClearNetworkMessage(error_type_);
+    ash::Shell::GetInstance()->system_tray_notifier()->
+        NotifyClearNetworkMessage(error_type_);
   }
 
   void SetTitle(const string16& title) {
@@ -86,8 +87,8 @@ class NetworkMessageNotification : public ash::NetworkTrayDelegate {
     callback_ = callback;
     std::vector<string16> links;
     links.push_back(link_text);
-    ash::Shell::GetInstance()->system_tray()->network_observer()->
-        SetNetworkMessage(this, error_type_, title_, message, links);
+    ash::Shell::GetInstance()->system_tray_notifier()->NotifySetNetworkMessage(
+        this, error_type_, title_, message, links);
   }
 
   void ShowAlways(const string16& message,
diff --git a/chrome/browser/chromeos/sms_observer.cc b/chrome/browser/chromeos/sms_observer.cc
index 866568f..431fc87 100644
--- a/chrome/browser/chromeos/sms_observer.cc
+++ b/chrome/browser/chromeos/sms_observer.cc
@@ -7,6 +7,7 @@
 #include "ash/shell.h"
 #include "ash/system/chromeos/network/sms_observer.h"
 #include "ash/system/tray/system_tray.h"
+#include "ash/system/tray/system_tray_notifier.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/chromeos/cros/cros_library.h"
 #include "grit/generated_resources.h"
@@ -111,8 +112,7 @@ void SmsObserver::OnNewMessage(const std::string& modem_device_path,
   base::DictionaryValue dict;
   dict.SetString(ash::kSmsNumberKey, message.number);
   dict.SetString(ash::kSmsTextKey, message.text);
-  if (ash::Shell::GetInstance()->status_area_widget())
-    ash::Shell::GetInstance()->system_tray()->sms_observer()->AddMessage(dict);
+  ash::Shell::GetInstance()->system_tray_notifier()->NotifyAddSmsMessage(dict);
 }
 
 }  // namespace chromeos
diff --git a/chrome/browser/chromeos/status/data_promo_notification.cc b/chrome/browser/chromeos/status/data_promo_notification.cc
index 6d1cfcf..2acb823 100644
--- a/chrome/browser/chromeos/status/data_promo_notification.cc
+++ b/chrome/browser/chromeos/status/data_promo_notification.cc
@@ -8,6 +8,7 @@
 #include "ash/shell_window_ids.h"
 #include "ash/system/chromeos/network/network_observer.h"
 #include "ash/system/tray/system_tray.h"
+#include "ash/system/tray/system_tray_notifier.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chromeos/cros/cros_library.h"
@@ -202,12 +203,9 @@ void DataPromoNotification::ShowOptionalMobileDataPromoNotification(
     links.push_back(l10n_util::GetStringUTF16(link_message_id));
     if (!deal_info_url_.empty())
       links.push_back(l10n_util::GetStringUTF16(IDS_LEARN_MORE));
-    if (ash::Shell::GetInstance()->system_tray()->network_observer()) {
-      ash::Shell::GetInstance()->system_tray()->network_observer()->
-          SetNetworkMessage(listener, ash::NetworkObserver::MESSAGE_DATA_PROMO,
-              string16(), message, links);
-    }
-
+    ash::Shell::GetInstance()->system_tray_notifier()->NotifySetNetworkMessage(
+        listener, ash::NetworkObserver::MESSAGE_DATA_PROMO,
+        string16(), message, links);
     check_for_promo_ = false;
     SetShow3gPromoNotification(false);
     if (carrier_deal_promo_pref != kNotificationCountPrefDefault)
@@ -216,11 +214,8 @@ void DataPromoNotification::ShowOptionalMobileDataPromoNotification(
 }
 
 void DataPromoNotification::CloseNotification() {
-  if (ash::Shell::GetInstance()->status_area_widget() &&
-      ash::Shell::GetInstance()->system_tray()->network_observer()) {
-    ash::Shell::GetInstance()->system_tray()->network_observer()->
-        ClearNetworkMessage(ash::NetworkObserver::MESSAGE_DATA_PROMO);
-  }
+  ash::Shell::GetInstance()->system_tray_notifier()->NotifyClearNetworkMessage(
+      ash::NetworkObserver::MESSAGE_DATA_PROMO);
 }
 
 }  // namespace chromeos
diff --git a/chrome/browser/chromeos/system/ash_system_tray_delegate.cc b/chrome/browser/chromeos/system/ash_system_tray_delegate.cc
index ee421bd..e3f0389 100644
--- a/chrome/browser/chromeos/system/ash_system_tray_delegate.cc
+++ b/chrome/browser/chromeos/system/ash_system_tray_delegate.cc
@@ -17,6 +17,7 @@
 #include "ash/system/power/power_status_observer.h"
 #include "ash/system/tray/system_tray.h"
 #include "ash/system/tray/system_tray_delegate.h"
+#include "ash/system/tray/system_tray_notifier.h"
 #include "ash/system/tray_accessibility.h"
 #include "ash/system/tray_caps_lock.h"
 #include "ash/system/user/update_observer.h"
@@ -176,8 +177,7 @@ class SystemTrayDelegate : public ash::SystemTrayDelegate,
         screen_locked_(false),
         connected_network_state_(STATE_UNKNOWN),
         data_promo_notification_(new DataPromoNotification()),
-        volume_control_delegate_(ALLOW_THIS_IN_INITIALIZER_LIST(
-            new VolumeController)) {
+        volume_control_delegate_(new VolumeController()) {
     // Register notifications on construction so that events such as
     // PROFILE_CREATED do not get missed if they happen before Initialize().
     registrar_.Add(this,
@@ -625,7 +625,7 @@ class SystemTrayDelegate : public ash::SystemTrayDelegate,
   }
 
   virtual void ToggleWifi() OVERRIDE {
-    GetSystemTray()->network_observer()->OnWillToggleWifi();
+    GetSystemTrayNotifier()->NotifyWillToggleWifi();
     network_menu_->ToggleWifi();
   }
 
@@ -739,6 +739,10 @@ class SystemTrayDelegate : public ash::SystemTrayDelegate,
     return ash::Shell::GetInstance()->system_tray();
   }
 
+  ash::SystemTrayNotifier* GetSystemTrayNotifier() {
+    return ash::Shell::GetInstance()->system_tray_notifier();
+  }
+
   // Returns the last active browser. If there is no such browser, creates a new
   // browser window with an empty tab and returns it.
   Browser* GetAppropriateBrowser() {
@@ -771,44 +775,22 @@ class SystemTrayDelegate : public ash::SystemTrayDelegate,
   void UpdateClockType(PrefServiceBase* service) {
     clock_type_ = service->GetBoolean(prefs::kUse24HourClock) ?
         base::k24HourClock : base::k12HourClock;
-    ash::ClockObserver* observer = GetSystemTray()->clock_observer();
-    if (observer)
-      observer->OnDateFormatChanged();
+    GetSystemTrayNotifier()->NotifyDateFormatChanged();
   }
 
   void UpdateShowLogoutButtonInTray(PrefServiceBase* service) {
-    ash::LogoutButtonObserver* observer =
-        GetSystemTray()->logout_button_observer();
-    if (observer) {
-      observer->OnShowLogoutButtonInTrayChanged(
-          service->GetBoolean(prefs::kShowLogoutButtonInTray));
-    }
-  }
-
-  void NotifyRefreshClock() {
-    ash::ClockObserver* observer = GetSystemTray()->clock_observer();
-    if (observer)
-      observer->Refresh();
+    GetSystemTrayNotifier()->NotifyShowLoginButtonChanged(
+        service->GetBoolean(prefs::kShowLogoutButtonInTray));
   }
 
   void NotifyRefreshNetwork() {
-    ash::NetworkObserver* observer = GetSystemTray()->network_observer();
     chromeos::NetworkLibrary* crosnet =
         chromeos::CrosLibrary::Get()->GetNetworkLibrary();
-    if (observer) {
-      ash::NetworkIconInfo info;
-      info.image = network_icon_->GetIconAndText(&info.description);
-      info.tray_icon_visible = network_icon_->ShouldShowIconInTray();
-      observer->OnNetworkRefresh(info);
-    }
-
-    ash::NetworkObserver* vpn_observer = GetSystemTray()->vpn_observer();
-    if (vpn_observer) {
-      ash::NetworkIconInfo info;
-      info.image = network_icon_->GetIconAndText(&info.description);
-      info.tray_icon_visible = network_icon_->ShouldShowIconInTray();
-      vpn_observer->OnNetworkRefresh(info);
-    }
+    ash::NetworkIconInfo info;
+    info.image = network_icon_->GetIconAndText(&info.description);
+    info.tray_icon_visible = network_icon_->ShouldShowIconInTray();
+    GetSystemTrayNotifier()->NotifyRefreshNetwork(info);
+    GetSystemTrayNotifier()->NotifyVpnRefreshNetwork(info);
 
     // Update Accessibility.
 
@@ -838,30 +820,6 @@ class SystemTrayDelegate : public ash::SystemTrayDelegate,
     connected_network_state_ = connected_network_state;
   }
 
-  void NotifyRefreshBluetooth() {
-    ash::BluetoothObserver* observer = GetSystemTray()->bluetooth_observer();
-    if (observer)
-      observer->OnBluetoothRefresh();
-  }
-
-  void NotifyBluetoothDiscoveringChanged() {
-    ash::BluetoothObserver* observer = GetSystemTray()->bluetooth_observer();
-    if (observer)
-      observer->OnBluetoothDiscoveringChanged();
-  }
-
-  void NotifyRefreshIME(bool show_message) {
-    ash::IMEObserver* observer = GetSystemTray()->ime_observer();
-    if (observer)
-      observer->OnIMERefresh(show_message);
-  }
-
-  void NotifyRefreshDrive(ash::DriveOperationStatusList& list) {
-    ash::DriveObserver* observer = GetSystemTray()->drive_observer();
-    if (observer)
-      observer->OnDriveRefresh(list);
-  }
-
   void RefreshNetworkObserver(NetworkLibrary* crosnet) {
     const Network* network = crosnet->active_network();
     std::string new_path = network ? network->service_path() : std::string();
@@ -983,29 +941,27 @@ class SystemTrayDelegate : public ash::SystemTrayDelegate,
   // Overridden from AudioHandler::VolumeObserver.
   virtual void OnVolumeChanged() OVERRIDE {
     float level = AudioHandler::GetInstance()->GetVolumePercent() / 100.f;
-    GetSystemTray()->audio_observer()->OnVolumeChanged(level);
+    GetSystemTrayNotifier()->NotifyVolumeChanged(level);
   }
 
   // Overridden from AudioHandler::VolumeObserver.
   virtual void OnMuteToggled() OVERRIDE {
-    GetSystemTray()->audio_observer()->OnMuteToggled();
+    GetSystemTrayNotifier()->NotifyMuteToggled();
   }
 
   // Overridden from PowerManagerClient::Observer.
   virtual void BrightnessChanged(int level, bool user_initiated) OVERRIDE {
-    GetSystemTray()->brightness_observer()->
-        OnBrightnessChanged(static_cast<double>(level), user_initiated);
+    double leveld = static_cast<double>(level);
+    GetSystemTrayNotifier()->NotifyBrightnessChanged(leveld, user_initiated);
   }
 
   virtual void PowerChanged(const PowerSupplyStatus& power_status) OVERRIDE {
     power_supply_status_ = power_status;
-    FOR_EACH_OBSERVER(ash::PowerStatusObserver,
-                      GetSystemTray()->power_status_observers(),
-                      OnPowerStatusChanged(power_status));
+    GetSystemTrayNotifier()->NotifyPowerStatusChanged(power_status);
   }
 
   virtual void SystemResumed() OVERRIDE {
-    NotifyRefreshClock();
+    GetSystemTrayNotifier()->NotifyRefreshClock();
   }
 
   // Overridden from SessionManagerClient::Observer.
@@ -1094,18 +1050,14 @@ class SystemTrayDelegate : public ash::SystemTrayDelegate,
             severity = ash::UpdateObserver::UPDATE_NORMAL;
             break;
         }
-        ash::UpdateObserver* observer = GetSystemTray()->update_observer();
-        if (observer)
-          observer->OnUpdateRecommended(severity);
+        GetSystemTrayNotifier()->NotifyUpdateRecommended(severity);
         break;
       }
       case chrome::NOTIFICATION_LOGIN_USER_IMAGE_CHANGED: {
         // This notification is also sent on login screen when user avatar
         // is loaded from file.
         if (GetUserLoginStatus() != ash::user::LOGGED_IN_NONE) {
-          ash::UserObserver* observer = GetSystemTray()->user_observer();
-          if (observer)
-            observer->OnUserUpdate();
+          GetSystemTrayNotifier()->NotifyUserUpdate();
         }
         break;
       }
@@ -1140,12 +1092,8 @@ class SystemTrayDelegate : public ash::SystemTrayDelegate,
       search_key_mapped_to_ =
           service->GetInteger(prefs::kLanguageRemapSearchKeyTo);
     } else if (pref == prefs::kSpokenFeedbackEnabled) {
-      ash::AccessibilityObserver* observer =
-          GetSystemTray()->accessibility_observer();
-      if (observer) {
-        observer->OnAccessibilityModeChanged(
-            service->GetBoolean(prefs::kSpokenFeedbackEnabled));
-      }
+      GetSystemTrayNotifier()->NotifyAccessibilityModeChanged(
+          service->GetBoolean(prefs::kSpokenFeedbackEnabled));
     } else if (pref == prefs::kShowLogoutButtonInTray) {
       UpdateShowLogoutButtonInTray(service);
     } else {
@@ -1156,19 +1104,19 @@ class SystemTrayDelegate : public ash::SystemTrayDelegate,
   // Overridden from InputMethodManager::Observer.
   virtual void InputMethodChanged(
       input_method::InputMethodManager* manager, bool show_message) OVERRIDE {
-    NotifyRefreshIME(show_message);
+    GetSystemTrayNotifier()->NotifyRefreshIME(show_message);
   }
 
   virtual void InputMethodPropertyChanged(
       input_method::InputMethodManager* manager) OVERRIDE {
-    NotifyRefreshIME(false);
+    GetSystemTrayNotifier()->NotifyRefreshIME(false);
   }
 
   // google_apis::DriveServiceObserver overrides.
   virtual void OnProgressUpdate(
       const google_apis::OperationProgressStatusList& list) OVERRIDE {
     std::vector<ash::DriveOperationStatus> ui_list = GetDriveStatusList(list);
-    NotifyRefreshDrive(ui_list);
+    GetSystemTrayNotifier()->NotifyRefreshDrive(ui_list);
 
     // If we have something to report right now (i.e. completion status only),
     // we need to delayed re-check the status in few seconds to ensure we
@@ -1217,38 +1165,38 @@ class SystemTrayDelegate : public ash::SystemTrayDelegate,
 
   // Overridden from system::TimezoneSettings::Observer.
   virtual void TimezoneChanged(const icu::TimeZone& timezone) OVERRIDE {
-    NotifyRefreshClock();
+    GetSystemTrayNotifier()->NotifyRefreshClock();
   }
 
   // Overridden from BluetoothAdapter::Observer.
   virtual void AdapterPresentChanged(device::BluetoothAdapter* adapter,
                                      bool present) OVERRIDE {
-    NotifyRefreshBluetooth();
+    GetSystemTrayNotifier()->NotifyRefreshBluetooth();
   }
 
   virtual void AdapterPoweredChanged(device::BluetoothAdapter* adapter,
                                      bool powered) OVERRIDE {
-    NotifyRefreshBluetooth();
+    GetSystemTrayNotifier()->NotifyRefreshBluetooth();
   }
 
   virtual void AdapterDiscoveringChanged(device::BluetoothAdapter* adapter,
                                          bool discovering) OVERRIDE {
-    NotifyBluetoothDiscoveringChanged();
+    GetSystemTrayNotifier()->NotifyBluetoothDiscoveringChanged();
   }
 
   virtual void DeviceAdded(device::BluetoothAdapter* adapter,
                            device::BluetoothDevice* device) OVERRIDE {
-    NotifyRefreshBluetooth();
+    GetSystemTrayNotifier()->NotifyRefreshBluetooth();
   }
 
   virtual void DeviceChanged(device::BluetoothAdapter* adapter,
                              device::BluetoothDevice* device) OVERRIDE {
-    NotifyRefreshBluetooth();
+    GetSystemTrayNotifier()->NotifyRefreshBluetooth();
   }
 
   virtual void DeviceRemoved(device::BluetoothAdapter* adapter,
                              device::BluetoothDevice* device) OVERRIDE {
-    NotifyRefreshBluetooth();
+    GetSystemTrayNotifier()->NotifyRefreshBluetooth();
   }
 
   // Overridden from SystemKeyEventListener::CapsLockObserver.
@@ -1257,10 +1205,8 @@ class SystemTrayDelegate : public ash::SystemTrayDelegate,
     if (!base::chromeos::IsRunningOnChromeOS() ||
         search_key_mapped_to_ == input_method::kCapsLockKey)
       search_mapped_to_caps_lock = true;
-
-    ash::CapsLockObserver* observer = GetSystemTray()->caps_lock_observer();
-    if (observer)
-      observer->OnCapsLockChanged(enabled, search_mapped_to_caps_lock);
+    GetSystemTrayNotifier()->NotifyCapsLockChanged(
+        enabled, search_mapped_to_caps_lock);
   }
 
   // Overridden from ash::NetworkTrayDelegate