ChromeOS: Implement minumal material design OOBE.

chrome/browser/resources/chromeos/login/oobe_buttons.js

+// Copyright 2016 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.
+
+Polymer({
+  is: 'oobe-next-button',
+
+  properties: {
+    disabled: {
+      type: Boolean,
+      value: false,
+    }
+  },
+
+  onClick_: function(e) {
+    if (this.disabled)
+      e.stopPropagation();
+  }
+});
+
+Polymer({
+  is: 'oobe-icon-button',
+
+  properties: {
+    disabled: {type: Boolean, value: false, reflectToAttribute: true},
+
+    icon: String,
+
+    ariaLabel: String
+  },
+
+  focus: function() {
+    this.$.iconButton.focus();
+  },
+
+  onClick_: function(e) {
+    if (this.disabled)
+      e.stopPropagation();
+  }
+});