Add chrome://nfc-debug for debugging NFC on Chrome OS.

chrome/browser/resources/chromeos/nfc_debug.css

+/* Copyright (c) 2013 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.
+ */
+
+body {
+  margin: 0
+}
+
+p {
+  white-space: pre-wrap;
+}
+
+label {
+  display: block;
+}
+
+h1 {
+  margin: 1%;
+}
+
+div.entity-div {
+  -webkit-box-shadow: 0 0 20px 2px #aaa;
+  box-shadow: 0 0 20px 2px #aaa;
+  display: inline-block;
+  margin: 10px 5px;
+  overflow: hidden;
+  padding: 10px;
+  vertical-align: top;
+}
+
+#nfc-adapter-info {
+  width: 165px;
+}
+
+#ndef-record-form {
+  width: 300px;
+}
+
+#nfc-tag-info,
+#nfc-peer-info {
+  width: 270px;
+  word-wrap: break-word;
+}
+
+#ndef-record-form input {
+  width: 99%;
+}
+
+.parameters-table td {
+  padding: 0 10px 10px 0;
+}
+
+.transition-in {
+  -webkit-transition: opacity 250ms ease-in-out;
+  opacity: 1;
+  transition: opacity 250ms ease-in-out;
+}
+
+.transition-out {
+  -webkit-transition: opacity 250ms ease-in-out;
+  opacity: 0.25;
+  transition: opacity 250ms ease-in-out;
+}
+
+hr {
+  background: #888;
+  border: 0;
+  border-bottom: 1px dashed #ccc;
+}
+
+div.record-key-value-div {
+  margin-bottom: 10px;
+}
+
+span.record-key-span,
+div.record-key-div {
+  font-style: italic;
+  font-weight: bold;
+  margin-right: 10px;
+}
+
+.record-value-div > * {
+  margin: 10px;
+}