[Extensions] Ensure ordering of extension [un]loaded, activated messages

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 556cc4f388d1cf775eb14147623418b4c4d5afd5..f9e143690694db4f694a2d3b986bcd080bde720f 100644
--- a/chrome/browser/extensions/extension_service.h
+++ b/chrome/browser/extensions/extension_service.h
@@ -65,6 +65,7 @@ class ExtensionSystem;
 class ExtensionUpdater;
 class ExternalInstallManager;
 class OneShotEvent;
+class RendererStartupHelper;
 class SharedModuleService;
 class UpdateObserver;
 }  // namespace extensions
@@ -711,6 +712,10 @@ class ExtensionService
   // The SharedModuleService used to check for import dependencies.
   std::unique_ptr<extensions::SharedModuleService> shared_module_service_;
 
+  // The associated RendererStartupHelper. Guaranteed to outlive the
+  // ExtensionSystem, and thus us.
+  extensions::RendererStartupHelper* renderer_helper_;
+
   base::ObserverList<extensions::UpdateObserver, true> update_observers_;
 
   // Migrates app data when upgrading a legacy packaged app to a platform app