Update documentation of Performance.timing/navigation

Source/core/timing/PerformanceNavigation.idl

Index: Source/core/timing/PerformanceNavigation.idl
diff --git a/Source/core/timing/PerformanceNavigation.idl b/Source/core/timing/PerformanceNavigation.idl
index 4ed6c06c89fc18eb35c91a63db074e0e58a96a61..30ee7b27a5ffe8d7086def43b6c8e574e51ff952 100644
--- a/Source/core/timing/PerformanceNavigation.idl
+++ b/Source/core/timing/PerformanceNavigation.idl
@@ -28,13 +28,10 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-// http://www.w3.org/TR/navigation-timing/#sec-navigation-info-interface
-
-// TODO(philipj): This interface been morphed into PerformanceNavigationTiming
-// in the latest spec:
-// https://w3c.github.io/navigation-timing/#sec-PerformanceNavigationTiming
+// https://w3c.github.io/navigation-timing/#the-performancenavigation-interface
 
 [
+    Exposed=Window,
     GarbageCollected
 ] interface PerformanceNavigation {
     const unsigned short TYPE_NAVIGATE = 0;
@@ -43,4 +40,5 @@
     const unsigned short TYPE_RESERVED = 255;
     readonly attribute unsigned short type;
     readonly attribute unsigned short redirectCount;
+    // TODO(philipj): serializer = {attribute};
 };