Remove NOTIFICATION_EXTENSION_ENABLED.

extensions/browser/extension_registry.h

Index: extensions/browser/extension_registry.h
diff --git a/extensions/browser/extension_registry.h b/extensions/browser/extension_registry.h
index 2b9d25ae39c97b38abebb25d2576b011d0f6c6af..ec39dc214b043a8c5ed286455105bcc00de956b2 100644
--- a/extensions/browser/extension_registry.h
+++ b/extensions/browser/extension_registry.h
@@ -13,6 +13,7 @@
 #include "base/observer_list.h"
 #include "base/version.h"
 #include "components/keyed_service/core/keyed_service.h"
+#include "extensions/browser/events/lazy_event_dispatch_util.h"
 #include "extensions/browser/uninstall_reason.h"
 #include "extensions/common/extension_set.h"
 #include "extensions/features/features.h"
@@ -181,6 +182,8 @@ class ExtensionRegistry : public KeyedService {
   // KeyedService implementation:
   void Shutdown() override;
 
+  LazyEventDispatchUtil* lazy_event_dispatch_util();
+
  private:
   // Extensions that are installed, enabled and not terminated.
   ExtensionSet enabled_extensions_;
@@ -204,10 +207,12 @@ class ExtensionRegistry : public KeyedService {
   // subset of |enabled_extensions_|.
   ExtensionSet ready_extensions_;
 
-  base::ObserverList<ExtensionRegistryObserver> observers_;
-
   content::BrowserContext* const browser_context_;
 
+  std::unique_ptr<LazyEventDispatchUtil> lazy_event_dispatch_util_;

[Devlin, 2017/05/23 21:30:36]

I think this would be better placed on EventRouter.

[lazyboy, 2017/05/23 23:19:08]

Done.

+
+  base::ObserverList<ExtensionRegistryObserver> observers_;
+
   DISALLOW_COPY_AND_ASSIGN(ExtensionRegistry);
 };