Remove NOTIFICATION_EXTENSION_ENABLED.

chrome/browser/extensions/extension_service.h

Index: chrome/browser/extensions/extension_service.h
diff --git a/chrome/browser/extensions/extension_service.h b/chrome/browser/extensions/extension_service.h
index 8ee853843ff07a03698afa01bf9b07c06cfbd2ad..c84ba47d2bb44845c6192111bfc9b14c6130dd0f 100644
--- a/chrome/browser/extensions/extension_service.h
+++ b/chrome/browser/extensions/extension_service.h
@@ -580,6 +580,11 @@ class ExtensionService
   // the actual profile objects to be destroyed.
   void OnProfileDestructionStarted();
 
+  // Upon reloading an extension, reconnects devtools to the extension if
+  // the extension has a lazy background page.
+  void MaybeReconnectDevtoolsToLazyBackgroundPage(
+      const extensions::Extension* extension_id);
+
   // Called on file task runner thread to uninstall extension.
   static void UninstallExtensionOnFileThread(
       const std::string& id,