Use ExtensionRegistryObserver instead of deprecated extension notification from c/b/extension

chrome/browser/extensions/api/storage/managed_value_store_cache.cc

Index: chrome/browser/extensions/api/storage/managed_value_store_cache.cc
diff --git a/chrome/browser/extensions/api/storage/managed_value_store_cache.cc b/chrome/browser/extensions/api/storage/managed_value_store_cache.cc
index 5134fd5c62edfcdfc32968e5c4f44ff8e2857cbd..c48eab6cda65fabcf12bcc2a75732cfe8641bf01 100644
--- a/chrome/browser/extensions/api/storage/managed_value_store_cache.cc
+++ b/chrome/browser/extensions/api/storage/managed_value_store_cache.cc
@@ -10,7 +10,7 @@
 #include "base/file_util.h"
 #include "base/logging.h"
 #include "base/memory/weak_ptr.h"
-#include "chrome/browser/chrome_notification_types.h"
+#include "base/scoped_observer.h"
 #include "chrome/browser/extensions/api/storage/policy_value_store.h"
 #include "chrome/browser/policy/profile_policy_connector.h"
 #include "chrome/browser/policy/profile_policy_connector_factory.h"
@@ -23,13 +23,10 @@
 #include "components/policy/core/common/schema_map.h"
 #include "components/policy/core/common/schema_registry.h"
 #include "content/public/browser/browser_thread.h"
-#include "content/public/browser/notification_details.h"
-#include "content/public/browser/notification_observer.h"
-#include "content/public/browser/notification_registrar.h"
-#include "content/public/browser/notification_source.h"
 #include "extensions/browser/api/storage/settings_storage_factory.h"
 #include "extensions/browser/extension_prefs.h"
 #include "extensions/browser/extension_registry.h"
+#include "extensions/browser/extension_registry_observer.h"
 #include "extensions/browser/extension_system.h"
 #include "extensions/browser/value_store/value_store_change.h"
 #include "extensions/common/api/storage.h"
@@ -44,6 +41,7 @@ using content::BrowserContext;
 using content::BrowserThread;
 
 namespace extensions {
+class ExtensionRegistry;
 
 namespace storage = core_api::storage;
 
@@ -67,17 +65,21 @@ const char kLegacyBrowserSupportExtensionId[] =
 // to fetch cloud policy for those extensions, and allows its providers to
 // selectively load only extension policy that has users.
 class ManagedValueStoreCache::ExtensionTracker
-    : public content::NotificationObserver {
+    : public ExtensionRegistryObserver {
  public:
   explicit ExtensionTracker(Profile* profile);
   virtual ~ExtensionTracker() {}
 
-  // NotificationObserver implementation:
-  virtual void Observe(int type,
-                       const content::NotificationSource& source,
-                       const content::NotificationDetails& details) OVERRIDE;
-
  private:
+  // ExtensionRegistryObserver implementation.
+  virtual void OnExtensionWillBeInstalled(
+      content::BrowserContext* browser_context,
+      const Extension* extension,
+      bool is_update,
+      const std::string& old_name) OVERRIDE;
+  virtual void OnExtensionUninstalled(content::BrowserContext* browser_context,
+                                      const Extension* extension) OVERRIDE;
+
   // Handler for the signal from ExtensionSystem::ready().
   void OnExtensionsReady();
 
@@ -93,7 +95,8 @@ class ManagedValueStoreCache::ExtensionTracker
   void Register(const policy::ComponentMap* components);
 
   Profile* profile_;
-  content::NotificationRegistrar registrar_;
+  ScopedObserver<ExtensionRegistry, ExtensionRegistryObserver>
+      extension_registry_observer_;
   policy::SchemaRegistry* schema_registry_;
   base::WeakPtrFactory<ExtensionTracker> weak_factory_;
 
@@ -102,16 +105,11 @@ class ManagedValueStoreCache::ExtensionTracker
 
 ManagedValueStoreCache::ExtensionTracker::ExtensionTracker(Profile* profile)
     : profile_(profile),
+      extension_registry_observer_(this),
       schema_registry_(
           policy::SchemaRegistryServiceFactory::GetForContext(profile)),
       weak_factory_(this) {
-  registrar_.Add(this,
-                 chrome::NOTIFICATION_EXTENSION_INSTALLED_DEPRECATED,
-                 content::Source<Profile>(profile_));
-  registrar_.Add(this,
-                 chrome::NOTIFICATION_EXTENSION_UNINSTALLED,
-                 content::Source<Profile>(profile_));
-
+  extension_registry_observer_.Add(ExtensionRegistry::Get(profile_));
   // Load schemas when the extension system is ready. It might be ready now.
   ExtensionSystem::Get(profile_)->ready().Post(
       FROM_HERE,
@@ -119,37 +117,27 @@ ManagedValueStoreCache::ExtensionTracker::ExtensionTracker(Profile* profile)
                  weak_factory_.GetWeakPtr()));
 }
 
-void ManagedValueStoreCache::ExtensionTracker::Observe(
-    int type,
-    const content::NotificationSource& source,
-    const content::NotificationDetails& details) {
+void ManagedValueStoreCache::ExtensionTracker::OnExtensionWillBeInstalled(
+    content::BrowserContext* browser_context,
+    const Extension* extension,
+    bool is_update,
+    const std::string& old_name) {
   // Some extensions are installed on the first run before the ExtensionSystem
   // becomes ready. Wait until all of them are ready before registering the
   // schemas of managed extensions, so that the policy loaders are reloaded at
   // most once.
   if (!ExtensionSystem::Get(profile_)->ready().is_signaled())
     return;
-
-  switch (type) {
-    case chrome::NOTIFICATION_EXTENSION_INSTALLED_DEPRECATED: {
-      scoped_ptr<ExtensionSet> added(new ExtensionSet);
-      added->Insert(
-          content::Details<InstalledExtensionInfo>(details)->extension);
-      LoadSchemas(added.Pass());
-      break;
-    }
-    case chrome::NOTIFICATION_EXTENSION_UNINSTALLED: {
-      const Extension* removed =
-          content::Details<const Extension>(details).ptr();
-      if (removed && UsesManagedStorage(removed)) {
-        schema_registry_->UnregisterComponent(policy::PolicyNamespace(
-            policy::POLICY_DOMAIN_EXTENSIONS, removed->id()));
-      }
-      break;
-    }
-    default:
-      NOTREACHED();
-      return;
+  scoped_ptr<ExtensionSet> added(new ExtensionSet);
+  added->Insert(extension);
+  LoadSchemas(added.Pass());
+}
+void ManagedValueStoreCache::ExtensionTracker::OnExtensionUninstalled(
+    content::BrowserContext* browser_context,
+    const Extension* extension) {

[Devlin, 2014/05/28 16:58:34]

I don't _think_ this can ever happen, but the if statement on line 130 used to
break in both notifications, whereas now the OnExtensionUninstalled still
executes.  Could you either make sure that an extension can never be uninstalled
if the system isn't ready (you wouldn't think it could/should happen, but you
never know), or add the check here, too?

[limasdf, 2014/05/28 17:38:43]

Done.
The reason why I removed is the comment says 'extesnions are installed'.
But obviously code doesn't cover only extension installed event. :)

+  if (extension && UsesManagedStorage(extension)) {
+    schema_registry_->UnregisterComponent(policy::PolicyNamespace(
+        policy::POLICY_DOMAIN_EXTENSIONS, extension->id()));
   }
 }