Add NotificationAction.action member

public/platform/modules/notifications/WebNotificationAction.h

Index: public/platform/modules/notifications/WebNotificationAction.h
diff --git a/public/platform/modules/notifications/WebNotificationAction.h b/public/platform/modules/notifications/WebNotificationAction.h
index 4516b8c218615297b9c2bac5bdbce9343285e49e..3a2026d588b9503a4eb3b36da1187ef2a0510f5b 100644
--- a/public/platform/modules/notifications/WebNotificationAction.h
+++ b/public/platform/modules/notifications/WebNotificationAction.h
@@ -15,11 +15,13 @@ struct WebNotificationAction {
     WebNotificationAction() = default;
     WebNotificationAction(const WebNotificationAction&) = default;
 
-    WebNotificationAction(const WebString& title)
-        : title(title)
+    WebNotificationAction(const WebString& action, const WebString& title)
+        : action(action)
+        , title(title)
     {
     }
 
+    WebString action;
     WebString title;
 };