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..6a20028809fc2906db47d5d4844eeb2861bf9b1d 100644
--- a/public/platform/modules/notifications/WebNotificationData.h
+++ b/public/platform/modules/notifications/WebNotificationData.h
@@ -23,7 +23,7 @@ struct WebNotificationData {
     {
     }
 
-    WebNotificationData(const WebString& title, Direction direction, const WebString& lang, const WebString& body, const WebString& tag, const WebURL& icon, bool silent)
+    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)
@@ -31,6 +31,7 @@ struct WebNotificationData {
         , tag(tag)
         , icon(icon)
         , silent(silent)
+        , data(data)

[Peter Beverloo, 2015/03/15 22:35:04]

Sorry -- as mentioned in the previous CL, you will still need to include the
"data"-less constructor in this CL until Chromium gets updated to always pass
|data|.

[Sanghyun Park, 2015/03/16 00:00:21]

Oops it's my mistake. Sorry.
How about make 1 more constructor like before?
WDYT?

[Sanghyun Park, 2015/03/16 00:00:21]

Oops, it's my mistake. Sorry...
I'll add "data"-less constructor.

     {
     }
 
@@ -41,6 +42,7 @@ struct WebNotificationData {
     WebString tag;
     WebURL icon;
     bool silent;
+    WebString data;
 };
 
 } // namespace blink