Use ExtensionRegistryObserver instead of deprecated extension notification from c/b/e/api.

This clean up alarm, declarative, idle, push_messaing API.

R=kalman@chromium.org
BUG=354046, 354458
TEST=unit_tests

Review URL: https://codereview.chromium.org/275383002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@270024 0039d316-1c4b-4281-b951-d872f2087c98

10 files changed, 178 insertions, 153 deletions

diff --git a/chrome/browser/extensions/api/alarms/alarm_manager.cc b/chrome/browser/extensions/api/alarms/alarm_manager.cc
index cc3267d..6866f2d 100644
--- a/chrome/browser/extensions/api/alarms/alarm_manager.cc
+++ b/chrome/browser/extensions/api/alarms/alarm_manager.cc
@@ -16,10 +16,10 @@
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/state_store.h"
-#include "chrome/browser/profiles/profile.h"
 #include "chrome/common/extensions/api/alarms.h"
 #include "content/public/browser/notification_service.h"
 #include "extensions/browser/event_router.h"
+#include "extensions/browser/extension_registry.h"
 #include "extensions/browser/extension_system.h"
 
 namespace extensions {
@@ -97,16 +97,16 @@ scoped_ptr<base::ListValue> AlarmsToValue(const std::vector<Alarm>& alarms) {
 // AlarmManager
 
 AlarmManager::AlarmManager(content::BrowserContext* context)
-    : profile_(Profile::FromBrowserContext(context)),
+    : browser_context_(context),
       clock_(new base::DefaultClock()),
-      delegate_(new DefaultAlarmDelegate(context)) {
+      delegate_(new DefaultAlarmDelegate(context)),
+      extension_registry_observer_(this) {
+  extension_registry_observer_.Add(ExtensionRegistry::Get(browser_context_));
   registrar_.Add(this,
-                 chrome::NOTIFICATION_EXTENSION_LOADED_DEPRECATED,
-                 content::Source<Profile>(profile_));
-  registrar_.Add(this, chrome::NOTIFICATION_EXTENSION_UNINSTALLED,
-                 content::Source<Profile>(profile_));
+                 chrome::NOTIFICATION_EXTENSION_UNINSTALLED,
+                 content::Source<content::BrowserContext>(browser_context_));
 
-  StateStore* storage = ExtensionSystem::Get(profile_)->state_store();
+  StateStore* storage = ExtensionSystem::Get(browser_context_)->state_store();
   if (storage)
     storage->RegisterKey(kRegisteredAlarms);
 }
@@ -226,8 +226,8 @@ AlarmManager::GetFactoryInstance() {
 }
 
 // static
-AlarmManager* AlarmManager::Get(Profile* profile) {
-  return BrowserContextKeyedAPIFactory<AlarmManager>::Get(profile);
+AlarmManager* AlarmManager::Get(content::BrowserContext* browser_context) {
+  return BrowserContextKeyedAPIFactory<AlarmManager>::Get(browser_context);
 }
 
 void AlarmManager::RemoveAlarmIterator(const AlarmIterator& iter) {
@@ -290,7 +290,7 @@ void AlarmManager::AddAlarmImpl(const std::string& extension_id,
 }
 
 void AlarmManager::WriteToStorage(const std::string& extension_id) {
-  StateStore* storage = ExtensionSystem::Get(profile_)->state_store();
+  StateStore* storage = ExtensionSystem::Get(browser_context_)->state_store();
   if (!storage)
     return;
 
@@ -410,35 +410,26 @@ void AlarmManager::RunWhenReady(
     it->second.push(action);
 }
 
+void AlarmManager::OnExtensionLoaded(content::BrowserContext* browser_context,
+                                     const Extension* extension) {
+  StateStore* storage = ExtensionSystem::Get(browser_context_)->state_store();
+  if (storage) {
+    ready_actions_.insert(ReadyMap::value_type(extension->id(), ReadyQueue()));
+    storage->GetExtensionValue(
+        extension->id(),
+        kRegisteredAlarms,
+        base::Bind(
+            &AlarmManager::ReadFromStorage, AsWeakPtr(), extension->id()));
+  }
+}
+
 void AlarmManager::Observe(
     int type,
     const content::NotificationSource& source,
     const content::NotificationDetails& details) {
-  switch (type) {
-    case chrome::NOTIFICATION_EXTENSION_LOADED_DEPRECATED: {
-      const Extension* extension =
-          content::Details<const Extension>(details).ptr();
-      StateStore* storage = ExtensionSystem::Get(profile_)->state_store();
-      if (storage) {
-        ready_actions_.insert(
-            ReadyMap::value_type(extension->id(), ReadyQueue()));
-        storage->GetExtensionValue(extension->id(), kRegisteredAlarms,
-            base::Bind(&AlarmManager::ReadFromStorage,
-                       AsWeakPtr(), extension->id()));
-      }
-      break;
-    }
-    case chrome::NOTIFICATION_EXTENSION_UNINSTALLED: {
-      const Extension* extension =
-          content::Details<const Extension>(details).ptr();
-      RemoveAllAlarms(
-          extension->id(), base::Bind(RemoveAllOnUninstallCallback));
-      break;
-    }
-    default:
-      NOTREACHED();
-      break;
-  }
+  DCHECK_EQ(type, chrome::NOTIFICATION_EXTENSION_UNINSTALLED);
+  const Extension* extension = content::Details<const Extension>(details).ptr();
+  RemoveAllAlarms(extension->id(), base::Bind(RemoveAllOnUninstallCallback));
 }
 
 // AlarmManager::Alarm
diff --git a/chrome/browser/extensions/api/alarms/alarm_manager.h b/chrome/browser/extensions/api/alarms/alarm_manager.h
index 04515f1..95cfabc 100644
--- a/chrome/browser/extensions/api/alarms/alarm_manager.h
+++ b/chrome/browser/extensions/api/alarms/alarm_manager.h
@@ -12,14 +12,14 @@
 
 #include "base/callback.h"
 #include "base/memory/weak_ptr.h"
+#include "base/scoped_observer.h"
 #include "base/timer/timer.h"
 #include "chrome/common/extensions/api/alarms.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "extensions/browser/browser_context_keyed_api_factory.h"
 #include "extensions/browser/extension_function.h"
-
-class Profile;
+#include "extensions/browser/extension_registry_observer.h"
 
 namespace base {
 class Clock;
@@ -30,8 +30,8 @@ class BrowserContext;
 }  // namespace content
 
 namespace extensions {
-
 class ExtensionAlarmsSchedulingTest;
+class ExtensionRegistry;
 
 struct Alarm {
   Alarm();
@@ -57,6 +57,7 @@ struct Alarm {
 // There is one manager per virtual Profile.
 class AlarmManager : public BrowserContextKeyedAPI,
                      public content::NotificationObserver,
+                     public ExtensionRegistryObserver,
                      public base::SupportsWeakPtr<AlarmManager> {
  public:
   typedef std::vector<Alarm> AlarmList;
@@ -114,8 +115,8 @@ class AlarmManager : public BrowserContextKeyedAPI,
   // BrowserContextKeyedAPI implementation.
   static BrowserContextKeyedAPIFactory<AlarmManager>* GetFactoryInstance();
 
-  // Convenience method to get the AlarmManager for a profile.
-  static AlarmManager* Get(Profile* profile);
+  // Convenience method to get the AlarmManager for a content::BrowserContext.
+  static AlarmManager* Get(content::BrowserContext* browser_context);
 
  private:
   friend void RunScheduleNextPoll(AlarmManager*);
@@ -208,17 +209,25 @@ class AlarmManager : public BrowserContextKeyedAPI,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
 
+  // Overridden from extensions::ExtensionRegistryObserver.
+  virtual void OnExtensionLoaded(content::BrowserContext* browser_context,
+                                 const Extension* extension) OVERRIDE;
+
   // BrowserContextKeyedAPI implementation.
   static const char* service_name() {
     return "AlarmManager";
   }
   static const bool kServiceHasOwnInstanceInIncognito = true;
 
-  Profile* const profile_;
+  content::BrowserContext* const browser_context_;
   scoped_ptr<base::Clock> clock_;
   content::NotificationRegistrar registrar_;
   scoped_ptr<Delegate> delegate_;
 
+  // Listen to extension load notifications.
+  ScopedObserver<ExtensionRegistry, ExtensionRegistryObserver>
+      extension_registry_observer_;
+
   // The timer for this alarm manager.
   base::OneShotTimer<AlarmManager> timer_;
 
diff --git a/chrome/browser/extensions/api/alarms/alarms_api.cc b/chrome/browser/extensions/api/alarms/alarms_api.cc
index 4de1670..b8db084 100644
--- a/chrome/browser/extensions/api/alarms/alarms_api.cc
+++ b/chrome/browser/extensions/api/alarms/alarms_api.cc
@@ -119,7 +119,7 @@ bool AlarmsCreateFunction::RunAsync() {
                   Manifest::IsUnpackedLocation(GetExtension()->location()) ?
                   kDevDelayMinimum : kReleaseDelayMinimum),
               clock_->Now());
-  AlarmManager::Get(GetProfile())->AddAlarm(
+  AlarmManager::Get(browser_context())->AddAlarm(
       extension_id(), alarm, base::Bind(&AlarmsCreateFunction::Callback, this));
 
   return true;
@@ -134,7 +134,7 @@ bool AlarmsGetFunction::RunAsync() {
   EXTENSION_FUNCTION_VALIDATE(params.get());
 
   std::string name = params->name.get() ? *params->name : kDefaultAlarmName;
-  AlarmManager::Get(GetProfile())
+  AlarmManager::Get(browser_context())
       ->GetAlarm(extension_id(),
                  name,
                  base::Bind(&AlarmsGetFunction::Callback, this, name));
@@ -151,7 +151,7 @@ void AlarmsGetFunction::Callback(
 }
 
 bool AlarmsGetAllFunction::RunAsync() {
-  AlarmManager::Get(GetProfile())->GetAllAlarms(
+  AlarmManager::Get(browser_context())->GetAllAlarms(
       extension_id(), base::Bind(&AlarmsGetAllFunction::Callback, this));
   return true;
 }
@@ -176,7 +176,7 @@ bool AlarmsClearFunction::RunAsync() {
   EXTENSION_FUNCTION_VALIDATE(params.get());
 
   std::string name = params->name.get() ? *params->name : kDefaultAlarmName;
-  AlarmManager::Get(GetProfile())
+  AlarmManager::Get(browser_context())
       ->RemoveAlarm(extension_id(),
                     name,
                     base::Bind(&AlarmsClearFunction::Callback, this, name));
@@ -190,7 +190,7 @@ void AlarmsClearFunction::Callback(const std::string& name, bool success) {
 }
 
 bool AlarmsClearAllFunction::RunAsync() {
-  AlarmManager::Get(GetProfile())->RemoveAllAlarms(
+  AlarmManager::Get(browser_context())->RemoveAllAlarms(
       extension_id(), base::Bind(&AlarmsClearAllFunction::Callback, this));
   return true;
 }
diff --git a/chrome/browser/extensions/api/declarative/rules_registry_service.cc b/chrome/browser/extensions/api/declarative/rules_registry_service.cc
index 42d0ca4..567dd4e 100644
--- a/chrome/browser/extensions/api/declarative/rules_registry_service.cc
+++ b/chrome/browser/extensions/api/declarative/rules_registry_service.cc
@@ -20,6 +20,7 @@
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/notification_source.h"
 #include "content/public/browser/render_process_host.h"
+#include "extensions/browser/extension_registry.h"
 #include "extensions/common/extension.h"
 
 namespace extensions {
@@ -43,17 +44,13 @@ bool IsWebView(const RulesRegistryService::WebViewKey& webview_key) {
 
 RulesRegistryService::RulesRegistryService(content::BrowserContext* context)
     : content_rules_registry_(NULL),
+      extension_registry_observer_(this),
       profile_(Profile::FromBrowserContext(context)) {
   if (profile_) {
-    registrar_.Add(this,
-                   chrome::NOTIFICATION_EXTENSION_UNLOADED_DEPRECATED,
-                   content::Source<Profile>(profile_->GetOriginalProfile()));
+    extension_registry_observer_.Add(ExtensionRegistry::Get(profile_));
     registrar_.Add(this,
                    chrome::NOTIFICATION_EXTENSION_UNINSTALLED,
                    content::Source<Profile>(profile_->GetOriginalProfile()));
-    registrar_.Add(this,
-                   chrome::NOTIFICATION_EXTENSION_LOADED_DEPRECATED,
-                   content::Source<Profile>(profile_->GetOriginalProfile()));
     registrar_.Add(
         this, content::NOTIFICATION_RENDERER_PROCESS_TERMINATED,
         content::NotificationService::AllBrowserContextsAndSources());
@@ -206,18 +203,24 @@ void RulesRegistryService::NotifyRegistriesHelper(
   }
 }
 
+void RulesRegistryService::OnExtensionLoaded(
+    content::BrowserContext* browser_context,
+    const Extension* extension) {
+  NotifyRegistriesHelper(&RulesRegistry::OnExtensionLoaded, extension->id());
+}
+
+void RulesRegistryService::OnExtensionUnloaded(
+    content::BrowserContext* browser_context,
+    const Extension* extension,
+    UnloadedExtensionInfo::Reason reason) {
+  NotifyRegistriesHelper(&RulesRegistry::OnExtensionUnloaded, extension->id());
+}
+
 void RulesRegistryService::Observe(
     int type,
     const content::NotificationSource& source,
     const content::NotificationDetails& details) {
   switch (type) {
-    case chrome::NOTIFICATION_EXTENSION_UNLOADED_DEPRECATED: {
-      const Extension* extension =
-          content::Details<UnloadedExtensionInfo>(details)->extension;
-      NotifyRegistriesHelper(&RulesRegistry::OnExtensionUnloaded,
-                             extension->id());
-      break;
-    }
     case chrome::NOTIFICATION_EXTENSION_UNINSTALLED: {
       const Extension* extension =
           content::Details<const Extension>(details).ptr();
@@ -225,13 +228,6 @@ void RulesRegistryService::Observe(
                              extension->id());
       break;
     }
-    case chrome::NOTIFICATION_EXTENSION_LOADED_DEPRECATED: {
-      const Extension* extension =
-          content::Details<const Extension>(details).ptr();
-      NotifyRegistriesHelper(&RulesRegistry::OnExtensionLoaded,
-                             extension->id());
-      break;
-    }
     case content::NOTIFICATION_RENDERER_PROCESS_TERMINATED: {
       content::RenderProcessHost* process =
           content::Source<content::RenderProcessHost>(source).ptr();
diff --git a/chrome/browser/extensions/api/declarative/rules_registry_service.h b/chrome/browser/extensions/api/declarative/rules_registry_service.h
index ae23372..97097ea 100644
--- a/chrome/browser/extensions/api/declarative/rules_registry_service.h
+++ b/chrome/browser/extensions/api/declarative/rules_registry_service.h
@@ -12,11 +12,13 @@
 #include "base/callback_forward.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_vector.h"
+#include "base/scoped_observer.h"
 #include "chrome/browser/extensions/api/declarative/rules_registry.h"
 #include "chrome/browser/profiles/profile.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "extensions/browser/browser_context_keyed_api_factory.h"
+#include "extensions/browser/extension_registry_observer.h"
 
 class Profile;
 
@@ -27,6 +29,7 @@ class NotificationSource;
 
 namespace extensions {
 class ContentRulesRegistry;
+class ExtensionRegistry;
 class RulesRegistry;
 class RulesRegistryStorageDelegate;
 }
@@ -36,7 +39,8 @@ namespace extensions {
 // This class owns all RulesRegistries implementations of an ExtensionService.
 // This class lives on the UI thread.
 class RulesRegistryService : public BrowserContextKeyedAPI,
-                             public content::NotificationObserver {
+                             public content::NotificationObserver,
+                             public ExtensionRegistryObserver {
  public:
   typedef RulesRegistry::WebViewKey WebViewKey;
   struct RulesRegistryKey {
@@ -105,6 +109,14 @@ class RulesRegistryService : public BrowserContextKeyedAPI,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
 
+  // ExtensionRegistryObserver implementation.
+  virtual void OnExtensionLoaded(content::BrowserContext* browser_context,
+                                 const Extension* extension) OVERRIDE;
+  virtual void OnExtensionUnloaded(
+      content::BrowserContext* browser_context,
+      const Extension* extension,
+      UnloadedExtensionInfo::Reason reason) OVERRIDE;
+
   // Iterates over all registries, and calls |notification_callback| on them
   // with |extension_id| as the argument. If a registry lives on a different
   // thread, the call is posted to that thread, so no guarantee of synchronous
@@ -131,6 +143,10 @@ class RulesRegistryService : public BrowserContextKeyedAPI,
 
   content::NotificationRegistrar registrar_;
 
+  // Listen to extension load, unloaded notification.
+  ScopedObserver<ExtensionRegistry, ExtensionRegistryObserver>
+      extension_registry_observer_;
+
   Profile* profile_;
 
   DISALLOW_COPY_AND_ASSIGN(RulesRegistryService);
diff --git a/chrome/browser/extensions/api/idle/idle_api_unittest.cc b/chrome/browser/extensions/api/idle/idle_api_unittest.cc
index 83c03cb..cb49004 100644
--- a/chrome/browser/extensions/api/idle/idle_api_unittest.cc
+++ b/chrome/browser/extensions/api/idle/idle_api_unittest.cc
@@ -17,6 +17,7 @@
 #include "content/public/browser/notification_details.h"
 #include "content/public/browser/notification_source.h"
 #include "extensions/browser/event_router.h"
+#include "extensions/browser/extension_registry.h"
 #include "extensions/common/extension.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -509,12 +510,9 @@ TEST_F(IdleTest, UnloadCleanup) {
   }
 
   // Threshold will reset after unload (and listen count == 0)
-  UnloadedExtensionInfo details(extension(),
-                                UnloadedExtensionInfo::REASON_UNINSTALL);
-  idle_manager_->Observe(
-      chrome::NOTIFICATION_EXTENSION_UNLOADED_DEPRECATED,
-      content::Source<Profile>(browser()->profile()),
-      content::Details<UnloadedExtensionInfo>(&details));
+  ExtensionRegistry* registry = ExtensionRegistry::Get(browser()->profile());
+  registry->TriggerOnUnloaded(extension(),
+                              UnloadedExtensionInfo::REASON_UNINSTALL);
 
   {
     ScopedListen listen(idle_manager_, extension()->id());
@@ -530,24 +528,18 @@ TEST_F(IdleTest, UnloadCleanup) {
 
 // Verifies that unloading an extension with no listeners or threshold works.
 TEST_F(IdleTest, UnloadOnly) {
-  UnloadedExtensionInfo details(extension(),
-                                UnloadedExtensionInfo::REASON_UNINSTALL);
-  idle_manager_->Observe(
-      chrome::NOTIFICATION_EXTENSION_UNLOADED_DEPRECATED,
-      content::Source<Profile>(browser()->profile()),
-      content::Details<UnloadedExtensionInfo>(&details));
+  ExtensionRegistry* registry = ExtensionRegistry::Get(browser()->profile());
+  registry->TriggerOnUnloaded(extension(),
+                              UnloadedExtensionInfo::REASON_UNINSTALL);
 }
 
 // Verifies that its ok for the unload notification to happen before all the
 // listener removals.
 TEST_F(IdleTest, UnloadWhileListening) {
   ScopedListen listen(idle_manager_, extension()->id());
-  UnloadedExtensionInfo details(extension(),
-                                UnloadedExtensionInfo::REASON_UNINSTALL);
-  idle_manager_->Observe(
-      chrome::NOTIFICATION_EXTENSION_UNLOADED_DEPRECATED,
-      content::Source<Profile>(browser()->profile()),
-      content::Details<UnloadedExtensionInfo>(&details));
+  ExtensionRegistry* registry = ExtensionRegistry::Get(browser()->profile());
+  registry->TriggerOnUnloaded(extension(),
+                              UnloadedExtensionInfo::REASON_UNINSTALL);
 }
 
 // Verifies that re-adding a listener after a state change doesn't immediately
diff --git a/chrome/browser/extensions/api/idle/idle_manager.cc b/chrome/browser/extensions/api/idle/idle_manager.cc
index 6e97ec0..ab88387 100644
--- a/chrome/browser/extensions/api/idle/idle_manager.cc
+++ b/chrome/browser/extensions/api/idle/idle_manager.cc
@@ -7,14 +7,12 @@
 #include <utility>
 
 #include "base/stl_util.h"
-#include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/extensions/api/idle/idle_api_constants.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/extensions/api/idle.h"
 #include "chrome/common/extensions/extension_constants.h"
-#include "content/public/browser/notification_details.h"
-#include "content/public/browser/notification_source.h"
 #include "extensions/browser/event_router.h"
+#include "extensions/browser/extension_registry.h"
 #include "extensions/common/extension.h"
 
 namespace keys = extensions::idle_api_constants;
@@ -125,15 +123,15 @@ IdleManager::IdleManager(Profile* profile)
       last_state_(IDLE_STATE_ACTIVE),
       weak_factory_(this),
       idle_time_provider_(new DefaultIdleProvider()),
-      event_delegate_(new DefaultEventDelegate(profile)) {
+      event_delegate_(new DefaultEventDelegate(profile)),
+      extension_registry_observer_(this) {
 }
 
 IdleManager::~IdleManager() {
 }
 
 void IdleManager::Init() {
-  registrar_.Add(this, chrome::NOTIFICATION_EXTENSION_UNLOADED_DEPRECATED,
-                 content::Source<Profile>(profile_->GetOriginalProfile()));
+  extension_registry_observer_.Add(ExtensionRegistry::Get(profile_));
   event_delegate_->RegisterObserver(this);
 }
 
@@ -142,18 +140,11 @@ void IdleManager::Shutdown() {
   event_delegate_->UnregisterObserver(this);
 }
 
-void IdleManager::Observe(int type,
-                          const content::NotificationSource& source,
-                          const content::NotificationDetails& details) {
+void IdleManager::OnExtensionUnloaded(content::BrowserContext* browser_context,
+                                      const Extension* extension,
+                                      UnloadedExtensionInfo::Reason reason) {
   DCHECK(thread_checker_.CalledOnValidThread());
-
-  if (type == chrome::NOTIFICATION_EXTENSION_UNLOADED_DEPRECATED) {
-    const Extension* extension =
-        content::Details<extensions::UnloadedExtensionInfo>(details)->extension;
-    monitors_.erase(extension->id());
-  } else {
-    NOTREACHED();
-  }
+  monitors_.erase(extension->id());
 }
 
 void IdleManager::OnListenerAdded(const EventListenerInfo& details) {
diff --git a/chrome/browser/extensions/api/idle/idle_manager.h b/chrome/browser/extensions/api/idle/idle_manager.h
index e93b0b2..4752917 100644
--- a/chrome/browser/extensions/api/idle/idle_manager.h
+++ b/chrome/browser/extensions/api/idle/idle_manager.h
@@ -11,13 +11,13 @@
 #include "base/callback_forward.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/weak_ptr.h"
+#include "base/scoped_observer.h"
 #include "base/threading/thread_checker.h"
 #include "base/timer/timer.h"
 #include "chrome/browser/idle.h"
 #include "components/keyed_service/core/keyed_service.h"
-#include "content/public/browser/notification_observer.h"
-#include "content/public/browser/notification_registrar.h"
 #include "extensions/browser/event_router.h"
+#include "extensions/browser/extension_registry_observer.h"
 
 namespace base {
 class StringValue;
@@ -26,6 +26,7 @@ class StringValue;
 class Profile;
 
 namespace extensions {
+class ExtensionRegistry;
 
 typedef base::Callback<void(IdleState)> QueryStateCallback;
 
@@ -37,7 +38,7 @@ struct IdleMonitor {
   int threshold;
 };
 
-class IdleManager : public content::NotificationObserver,
+class IdleManager : public ExtensionRegistryObserver,
                     public EventRouter::Observer,
                     public KeyedService {
  public:
@@ -75,10 +76,11 @@ class IdleManager : public content::NotificationObserver,
   // KeyedService implementation.
   virtual void Shutdown() OVERRIDE;
 
-  // content::NotificationDelegate implementation.
-  virtual void Observe(int type,
-                       const content::NotificationSource& source,
-                       const content::NotificationDetails& details) OVERRIDE;
+  // ExtensionRegistryObserver implementation.
+  virtual void OnExtensionUnloaded(
+      content::BrowserContext* browser_context,
+      const Extension* extension,
+      UnloadedExtensionInfo::Reason reason) OVERRIDE;
 
   // EventRouter::Observer implementation.
   virtual void OnListenerAdded(const EventListenerInfo& details) OVERRIDE;
@@ -125,13 +127,16 @@ class IdleManager : public content::NotificationObserver,
 
   base::RepeatingTimer<IdleManager> poll_timer_;
   base::WeakPtrFactory<IdleManager> weak_factory_;
-  content::NotificationRegistrar registrar_;
 
   scoped_ptr<IdleTimeProvider> idle_time_provider_;
   scoped_ptr<EventDelegate> event_delegate_;
 
   base::ThreadChecker thread_checker_;
 
+  // Listen to extension unloaded notification.
+  ScopedObserver<ExtensionRegistry, ExtensionRegistryObserver>
+      extension_registry_observer_;
+
   DISALLOW_COPY_AND_ASSIGN(IdleManager);
 };
 
diff --git a/chrome/browser/extensions/api/push_messaging/push_messaging_api.cc b/chrome/browser/extensions/api/push_messaging/push_messaging_api.cc
index 95684dd..e1effd90 100644
--- a/chrome/browser/extensions/api/push_messaging/push_messaging_api.cc
+++ b/chrome/browser/extensions/api/push_messaging/push_messaging_api.cc
@@ -28,6 +28,7 @@
 #include "content/public/browser/notification_details.h"
 #include "content/public/browser/notification_source.h"
 #include "extensions/browser/event_router.h"
+#include "extensions/browser/extension_registry.h"
 #include "extensions/browser/extension_system_provider.h"
 #include "extensions/browser/extensions_browser_client.h"
 #include "extensions/common/extension.h"
@@ -75,8 +76,7 @@ void PushMessagingEventRouter::OnMessage(const std::string& extension_id,
            << "' extension = '" << extension_id << "'";
 
   scoped_ptr<base::ListValue> args(glue::OnMessage::Create(message));
-  scoped_ptr<extensions::Event> event(
-      new extensions::Event(glue::OnMessage::kEventName, args.Pass()));
+  scoped_ptr<Event> event(new Event(glue::OnMessage::kEventName, args.Pass()));
   event->restrict_to_browser_context = profile_;
   EventRouter::Get(profile_)->DispatchEventToExtension(
       extension_id, event.Pass());
@@ -287,14 +287,11 @@ void PushMessagingGetChannelIdFunction::OnObfuscatedGaiaIdFetchFailure(
 }
 
 PushMessagingAPI::PushMessagingAPI(content::BrowserContext* context)
-    : profile_(Profile::FromBrowserContext(context)) {
+    : extension_registry_observer_(this),
+      profile_(Profile::FromBrowserContext(context)) {
+  extension_registry_observer_.Add(ExtensionRegistry::Get(profile_));
   registrar_.Add(this, chrome::NOTIFICATION_EXTENSION_INSTALLED,
                  content::Source<Profile>(profile_->GetOriginalProfile()));
-  registrar_.Add(this,
-                 chrome::NOTIFICATION_EXTENSION_LOADED_DEPRECATED,
-                 content::Source<Profile>(profile_->GetOriginalProfile()));
-  registrar_.Add(this, chrome::NOTIFICATION_EXTENSION_UNLOADED_DEPRECATED,
-                 content::Source<Profile>(profile_->GetOriginalProfile()));
 }
 
 PushMessagingAPI::~PushMessagingAPI() {
@@ -319,46 +316,56 @@ PushMessagingAPI::GetFactoryInstance() {
   return g_factory.Pointer();
 }
 
-void PushMessagingAPI::Observe(int type,
-                               const content::NotificationSource& source,
-                               const content::NotificationDetails& details) {
+bool PushMessagingAPI::InitEventRouterAndHandler() {
   invalidation::InvalidationService* invalidation_service =
       invalidation::InvalidationServiceFactory::GetForProfile(profile_);
   if (!invalidation_service)
-    return;
+    return false;
 
   if (!event_router_)
     event_router_.reset(new PushMessagingEventRouter(profile_));
   if (!handler_) {
-    handler_.reset(new PushMessagingInvalidationHandler(
-        invalidation_service, event_router_.get()));
+    handler_.reset(new PushMessagingInvalidationHandler(invalidation_service,
+                                                        event_router_.get()));
   }
-  switch (type) {
-    case chrome::NOTIFICATION_EXTENSION_INSTALLED: {
-      const Extension* extension =
-          content::Details<const InstalledExtensionInfo>(details)->extension;
-      if (extension->HasAPIPermission(APIPermission::kPushMessaging)) {
-        handler_->SuppressInitialInvalidationsForExtension(extension->id());
-      }
-      break;
-    }
-    case chrome::NOTIFICATION_EXTENSION_LOADED_DEPRECATED: {
-      const Extension* extension = content::Details<Extension>(details).ptr();
-      if (extension->HasAPIPermission(APIPermission::kPushMessaging)) {
-        handler_->RegisterExtension(extension->id());
-      }
-      break;
-    }
-    case chrome::NOTIFICATION_EXTENSION_UNLOADED_DEPRECATED: {
-      const Extension* extension =
-          content::Details<UnloadedExtensionInfo>(details)->extension;
-      if (extension->HasAPIPermission(APIPermission::kPushMessaging)) {
-        handler_->UnregisterExtension(extension->id());
-      }
-      break;
-    }
-    default:
-      NOTREACHED();
+
+  return true;
+}
+
+void PushMessagingAPI::OnExtensionLoaded(
+    content::BrowserContext* browser_context,
+    const Extension* extension) {
+  if (!InitEventRouterAndHandler())
+    return;
+
+  if (extension->HasAPIPermission(APIPermission::kPushMessaging)) {
+    handler_->RegisterExtension(extension->id());
+  }
+}
+
+void PushMessagingAPI::OnExtensionUnloaded(
+    content::BrowserContext* browser_context,
+    const Extension* extension,
+    UnloadedExtensionInfo::Reason reason) {
+  if (!InitEventRouterAndHandler())
+    return;
+
+  if (extension->HasAPIPermission(APIPermission::kPushMessaging)) {
+    handler_->UnregisterExtension(extension->id());
+  }
+}
+
+void PushMessagingAPI::Observe(int type,
+                               const content::NotificationSource& source,
+                               const content::NotificationDetails& details) {
+  DCHECK_EQ(type, chrome::NOTIFICATION_EXTENSION_INSTALLED);
+  if (!InitEventRouterAndHandler())
+    return;
+
+  const Extension* extension =
+      content::Details<const InstalledExtensionInfo>(details)->extension;
+  if (extension->HasAPIPermission(APIPermission::kPushMessaging)) {
+    handler_->SuppressInitialInvalidationsForExtension(extension->id());
   }
 }
 
diff --git a/chrome/browser/extensions/api/push_messaging/push_messaging_api.h b/chrome/browser/extensions/api/push_messaging/push_messaging_api.h
index 0b5884b..9600a28 100644
--- a/chrome/browser/extensions/api/push_messaging/push_messaging_api.h
+++ b/chrome/browser/extensions/api/push_messaging/push_messaging_api.h
@@ -11,6 +11,7 @@
 #include "base/compiler_specific.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/scoped_observer.h"
 #include "chrome/browser/extensions/api/push_messaging/obfuscated_gaia_id_fetcher.h"
 #include "chrome/browser/extensions/api/push_messaging/push_messaging_invalidation_handler_delegate.h"
 #include "chrome/browser/extensions/chrome_extension_function.h"
@@ -18,6 +19,7 @@
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "extensions/browser/browser_context_keyed_api_factory.h"
+#include "extensions/browser/extension_registry_observer.h"
 #include "google_apis/gaia/google_service_auth_error.h"
 #include "google_apis/gaia/oauth2_token_service.h"
 
@@ -28,7 +30,7 @@ class BrowserContext;
 }
 
 namespace extensions {
-
+class ExtensionRegistry;
 class PushMessagingInvalidationMapper;
 
 // Observes a single InvalidationHandler and generates onMessage events.
@@ -109,7 +111,8 @@ class PushMessagingGetChannelIdFunction
 };
 
 class PushMessagingAPI : public BrowserContextKeyedAPI,
-                         public content::NotificationObserver {
+                         public content::NotificationObserver,
+                         public ExtensionRegistryObserver {
  public:
   explicit PushMessagingAPI(content::BrowserContext* context);
   virtual ~PushMessagingAPI();
@@ -146,6 +149,17 @@ class PushMessagingAPI : public BrowserContextKeyedAPI,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
 
+  // Overridden from ExtensionRegistryObserver.
+  virtual void OnExtensionLoaded(content::BrowserContext* browser_context,
+                                 const Extension* extension) OVERRIDE;
+  virtual void OnExtensionUnloaded(
+      content::BrowserContext* browser_context,
+      const Extension* extension,
+      UnloadedExtensionInfo::Reason reason) OVERRIDE;
+
+  // Initialize |event_router_| and |handler_|.
+  bool InitEventRouterAndHandler();
+
   // Created lazily when an app or extension with the push messaging permission
   // is loaded.
   scoped_ptr<PushMessagingEventRouter> event_router_;
@@ -153,6 +167,10 @@ class PushMessagingAPI : public BrowserContextKeyedAPI,
 
   content::NotificationRegistrar registrar_;
 
+  // Listen to extension load, unload notifications.
+  ScopedObserver<ExtensionRegistry, ExtensionRegistryObserver>
+      extension_registry_observer_;
+
   Profile* profile_;
 
   DISALLOW_COPY_AND_ASSIGN(PushMessagingAPI);