Add Vibration API layout tests that inspect internal state.

Source/modules/vibration/testing/InternalsVibration.cpp

Index: Source/modules/vibration/testing/InternalsVibration.cpp
diff --git a/Source/modules/vibration/testing/InternalsVibration.cpp b/Source/modules/vibration/testing/InternalsVibration.cpp
index 09792a0fb24c0e5198de516f121e27b3776d1477..a22bb0117b29d31b7e92e679e2b6209a6bd107fe 100644
--- a/Source/modules/vibration/testing/InternalsVibration.cpp
+++ b/Source/modules/vibration/testing/InternalsVibration.cpp
@@ -43,4 +43,10 @@ bool InternalsVibration::isVibrating(Internals* internals, Document* document)
     return NavigatorVibration::from(document->page())->isVibrating();
 }
 
+Vector<unsigned> InternalsVibration::pendingVibrationPattern(Internals* internals, Document* document)
+{
+    ASSERT(internals && document && document->page());
+    return NavigatorVibration::from(document->page())->pattern();
+}
+
 } // namespace WebCore