[webnfc]: Step 1: Add NavigatorNfc, Nfc and Layout tests.

Source/modules/nfc/NavigatorNfc.idl

Index: Source/modules/nfc/NavigatorNfc.idl
diff --git a/Source/modules/nfc/NavigatorNfc.idl b/Source/modules/nfc/NavigatorNfc.idl
new file mode 100644
index 0000000000000000000000000000000000000000..fdfda8b736c01597ecf9920d37099df4a2cf899c
--- /dev/null
+++ b/Source/modules/nfc/NavigatorNfc.idl
@@ -0,0 +1,11 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// http://w3c.github.io/web-nfc/
+
+[
+  RuntimeEnabled=Nfc,
+] partial interface Navigator {
+    [CallWith=ExecutionContext] readonly attribute Nfc nfc;
+};