Remove PrefObserver usage, batch 3.

chrome/browser/chromeos/system/ash_system_tray_delegate.cc

Index: chrome/browser/chromeos/system/ash_system_tray_delegate.cc
diff --git a/chrome/browser/chromeos/system/ash_system_tray_delegate.cc b/chrome/browser/chromeos/system/ash_system_tray_delegate.cc
index 9ac78405ad2f5b8083346b689229034c196988d9..9816028cd42576ba66fc532580dff6126c3fdf2f 100644
--- a/chrome/browser/chromeos/system/ash_system_tray_delegate.cc
+++ b/chrome/browser/chromeos/system/ash_system_tray_delegate.cc
@@ -27,7 +27,6 @@
 #include "base/chromeos/chromeos_version.h"
 #include "base/logging.h"
 #include "base/memory/weak_ptr.h"
-#include "base/prefs/public/pref_observer.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chromeos/accessibility/accessibility_util.h"
@@ -153,7 +152,6 @@ class SystemTrayDelegate : public ash::SystemTrayDelegate,
                            public NetworkLibrary::NetworkManagerObserver,
                            public NetworkLibrary::NetworkObserver,
                            public NetworkLibrary::CellularDataPlanObserver,
-                           public PrefObserver,
                            public google_apis::DriveServiceObserver,
                            public content::NotificationObserver,
                            public input_method::InputMethodManager::Observer,
@@ -218,8 +216,11 @@ class SystemTrayDelegate : public ash::SystemTrayDelegate,
     if (SystemKeyEventListener::GetInstance())
       SystemKeyEventListener::GetInstance()->AddCapsLockObserver(this);
 
-    accessibility_enabled_.Init(prefs::kSpokenFeedbackEnabled,
-                                g_browser_process->local_state(), this);
+    accessibility_enabled_.Init(
+        prefs::kSpokenFeedbackEnabled,
+        g_browser_process->local_state(),
+        base::Bind(&SystemTrayDelegate::OnSpokenFeedbackEnabledChanged,
+                   base::Unretained(this)));
 
     network_icon_->SetResourceColorTheme(NetworkMenuIcon::COLOR_LIGHT);
     network_icon_dark_->SetResourceColorTheme(NetworkMenuIcon::COLOR_DARK);
@@ -752,11 +753,20 @@ class SystemTrayDelegate : public ash::SystemTrayDelegate,
     PrefService* prefs = profile->GetPrefs();
     pref_registrar_.reset(new PrefChangeRegistrar);
     pref_registrar_->Init(prefs);
-    pref_registrar_->Add(prefs::kUse24HourClock, this);
-    pref_registrar_->Add(prefs::kLanguageRemapSearchKeyTo, this);
-    pref_registrar_->Add(prefs::kShowLogoutButtonInTray, this);
-    UpdateClockType(prefs);
-    UpdateShowLogoutButtonInTray(prefs);
+    pref_registrar_->Add(
+        prefs::kUse24HourClock,
+        base::Bind(&SystemTrayDelegate::UpdateClockType,
+                   base::Unretained(this)));
+    pref_registrar_->Add(
+        prefs::kLanguageRemapSearchKeyTo,
+        base::Bind(&SystemTrayDelegate::OnLanguageRemapSearchKeyToChanged,
+                   base::Unretained(this)));
+    pref_registrar_->Add(
+        prefs::kShowLogoutButtonInTray,
+        base::Bind(&SystemTrayDelegate::UpdateShowLogoutButtonInTray,
+                   base::Unretained(this)));
+    UpdateClockType();
+    UpdateShowLogoutButtonInTray();
     search_key_mapped_to_ =
         profile->GetPrefs()->GetInteger(prefs::kLanguageRemapSearchKeyTo);
   }
@@ -769,20 +779,20 @@ class SystemTrayDelegate : public ash::SystemTrayDelegate,
     system_service->drive_service()->AddObserver(this);
   }
 
-  void UpdateClockType(PrefServiceBase* service) {
-    clock_type_ = service->GetBoolean(prefs::kUse24HourClock) ?
+  void UpdateClockType() {
+    clock_type_ = pref_registrar_->prefs()->GetBoolean(prefs::kUse24HourClock) ?
         base::k24HourClock : base::k12HourClock;
     ash::ClockObserver* observer = GetSystemTray()->clock_observer();
     if (observer)
       observer->OnDateFormatChanged();
   }
 
-  void UpdateShowLogoutButtonInTray(PrefServiceBase* service) {
+  void UpdateShowLogoutButtonInTray() {
     ash::LogoutButtonObserver* observer =
         GetSystemTray()->logout_button_observer();
     if (observer) {
       observer->OnShowLogoutButtonInTrayChanged(
-          service->GetBoolean(prefs::kShowLogoutButtonInTray));
+          pref_registrar_->prefs()->GetBoolean(prefs::kShowLogoutButtonInTray));
     }
   }
 
@@ -1133,24 +1143,18 @@ class SystemTrayDelegate : public ash::SystemTrayDelegate,
     }
   }
 
-  virtual void OnPreferenceChanged(PrefServiceBase* service,
-                                   const std::string& pref) OVERRIDE {
-    if (pref == prefs::kUse24HourClock) {
-      UpdateClockType(service);
-    } else if (pref == prefs::kLanguageRemapSearchKeyTo) {
-      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));
-      }
-    } else if (pref == prefs::kShowLogoutButtonInTray) {
-      UpdateShowLogoutButtonInTray(service);
-    } else {
-      NOTREACHED();
+  void OnLanguageRemapSearchKeyToChanged() {
+    search_key_mapped_to_ = pref_registrar_->prefs()->GetInteger(
+        prefs::kLanguageRemapSearchKeyTo);
+  }
+
+  void OnSpokenFeedbackEnabledChanged() {
+    ash::AccessibilityObserver* observer =
+        GetSystemTray()->accessibility_observer();
+    if (observer) {
+      observer->OnAccessibilityModeChanged(
+          accessibility_enabled_.prefs()->GetBoolean(
+              prefs::kSpokenFeedbackEnabled));
     }
   }