ChromeOS: Implement Update screen of material design OOBE.

chrome/browser/resources/chromeos/login/oobe_update.css

+/* 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. */
+
+#estimated-time-left,
+#progress-message,
+#cancel-hint {
+  font: 13px Roboto, sans-serif;
+  margin: 0 20px;
+}
+
+#estimated-time-left,
+#progress-message {
+  padding-top: 31px; /* = 44 - font size */
+}
+
+#checkingForUpdateCancelHint,
+#updatingCancelHint {
+  color: rgb(170, 0, 0);
+  padding: 0;
+}
+
+paper-progress {
+  --paper-progress-active-color: var(--google-blue-500);
+  --paper-progress-secondary-color: var(--google-blue-100);
+  bottom: 0;
+  height: 3px;
+  width: 100%;
+}