Add data property in persistent web notification

public/platform/modules/notifications/WebNotificationData.h

Index: public/platform/modules/notifications/WebNotificationData.h
diff --git a/public/platform/modules/notifications/WebNotificationData.h b/public/platform/modules/notifications/WebNotificationData.h
index 5b825d1598fbfd12cbfeebf3379122d578a513a3..c4973cb14b92f421903bc7c19f65b41eb207f81c 100644
--- a/public/platform/modules/notifications/WebNotificationData.h
+++ b/public/platform/modules/notifications/WebNotificationData.h
@@ -34,6 +34,18 @@ struct WebNotificationData {
     {
     }
 
+    WebNotificationData(const WebString& title, Direction direction, const WebString& lang, const WebString& body, const WebString& tag, const WebURL& icon, bool silent, const WebString& data)
+        : title(title)
+        , direction(direction)
+        , lang(lang)
+        , body(body)
+        , tag(tag)
+        , icon(icon)
+        , silent(silent)
+        , data(data)
+    {
+    }
+
     WebString title;
     Direction direction;
     WebString lang;
@@ -41,6 +53,7 @@ struct WebNotificationData {
     WebString tag;
     WebURL icon;
     bool silent;
+    WebString data;
 };
 
 } // namespace blink