Introduce NavigatorID IDL interface

Source/core/page/NavigatorID.idl

Index: Source/core/page/NavigatorID.idl
diff --git a/Source/core/svg/SVGUnknownElement.cpp b/Source/core/page/NavigatorID.idl
similarity index 87%
copy from Source/core/svg/SVGUnknownElement.cpp
copy to Source/core/page/NavigatorID.idl
index ecc0d2f2f186434ad83a947d92cca241c2bfa3b0..a0333ba3548e2586bdcdfcf3964961c68888fed7 100644
--- a/Source/core/svg/SVGUnknownElement.cpp
+++ b/Source/core/page/NavigatorID.idl
@@ -28,14 +28,11 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include "config.h"
-#include "core/svg/SVGUnknownElement.h"
-
-namespace WebCore {
-
-SVGUnknownElement::SVGUnknownElement(const QualifiedName& tagName, Document* document)
-    : SVGElement(tagName, document)
-{
-}
-
-} // namespace WebCore
+[
+    NoInterfaceObject
+] interface NavigatorID {
+    readonly attribute DOMString appName;
+    readonly attribute DOMString appVersion;
+    readonly attribute DOMString platform;
+    readonly attribute DOMString userAgent;
+};