Fix the extension activity log UI.

chrome/browser/ui/webui/extensions/extension_settings_handler.h

Index: chrome/browser/ui/webui/extensions/extension_settings_handler.h
diff --git a/chrome/browser/ui/webui/extensions/extension_settings_handler.h b/chrome/browser/ui/webui/extensions/extension_settings_handler.h
index ff6804c557dbde5ee458b2ffb49d5b83a936147d..dd1e0d93deeee73003123ef96a8428a6d06a7d5b 100644
--- a/chrome/browser/ui/webui/extensions/extension_settings_handler.h
+++ b/chrome/browser/ui/webui/extensions/extension_settings_handler.h
@@ -133,6 +133,9 @@ class ExtensionSettingsHandler : public content::WebUIMessageHandler,
   // Callback for "options" message.
   void HandleOptionsMessage(const base::ListValue* args);
 
+  // Callback for "activity" message.
+  void HandleActivityMessage(const base::ListValue* args);
+
   // Callback for "showButton" message.
   void HandleShowButtonMessage(const base::ListValue* args);