New post-sideload UI:

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 3e42906d86461e6b4c0cdf988a7d9dd3395a2da5..0b783c98090263b9a6cf540ba9129f850828047a 100644
--- a/chrome/browser/extensions/extension_service.h
+++ b/chrome/browser/extensions/extension_service.h
@@ -586,9 +586,8 @@ class ExtensionService
   // the member variable to make it easier to test the method in isolation.
   bool PopulateExtensionErrorUI(ExtensionErrorUI* extension_error_ui);
 
-  // Marks alertable extensions as acknowledged, after the user presses the
-  // accept button.
-  void HandleExtensionAlertAccept();
+  // Checks if there are any new external extensions to notify the user about.
+  void UpdateExternalExtensionAlert();
 
   // Given a (presumably just-installed) extension id, mark that extension as
   // acknowledged.
@@ -601,6 +600,10 @@ class ExtensionService
   // Called when the extension alert is closed.
   void HandleExtensionAlertClosed();
 
+  // Marks alertable extensions as acknowledged, after the user presses the
+  // accept button.
+  void HandleExtensionAlertAccept();
+
   // content::NotificationObserver
   virtual void Observe(int type,
                        const content::NotificationSource& source,