Supports the sound attribute to the Notification object

Source/modules/notifications/Notification.h

Index: Source/modules/notifications/Notification.h
diff --git a/Source/modules/notifications/Notification.h b/Source/modules/notifications/Notification.h
index c89970ab9cbe8a140bf47be35f61dee6ea9c60ec..63e4fc3861ae8551f1dd89213b312a435565e649 100644
--- a/Source/modules/notifications/Notification.h
+++ b/Source/modules/notifications/Notification.h
@@ -90,12 +90,14 @@ public:
     String body() const { return m_body; }
     String tag() const { return m_tag; }
     String icon() const { return m_iconUrl; }
+    String sound() const { return m_soundUrl; }
     NavigatorVibration::VibrationPattern vibrate(bool& isNull) const;
     bool silent() const { return m_silent; }
     ScriptValue data(ScriptState*) const;
 
     TextDirection direction() const;
     KURL iconURL() const { return m_iconUrl; }
+    KURL soundURL() const { return m_soundUrl; }
     SerializedScriptValue* serializedData() const { return m_serializedData.get(); }
 
     static String permissionString(WebNotificationPermission);
@@ -130,6 +132,7 @@ private:
     void setLang(const String& lang) { m_lang = lang; }
     void setBody(const String& body) { m_body = body; }
     void setIconUrl(KURL iconUrl) { m_iconUrl = iconUrl; }
+    void setSoundUrl(KURL soundUrl) { m_soundUrl = soundUrl; }
     void setTag(const String& tag) { m_tag = tag; }
     void setVibrate(const NavigatorVibration::VibrationPattern& vibrate) { m_vibrate = vibrate; }
     void setSilent(bool silent) { m_silent = silent; }
@@ -148,6 +151,7 @@ private:
     RefPtr<SerializedScriptValue> m_serializedData;
 
     KURL m_iconUrl;
+    KURL m_soundUrl;
 
     // Notifications can either be bound to the page, which means they're identified by
     // their delegate, or persistent, which means they're identified by a persistent Id