WebUI: Update some more uses of the old-style i18ntemplate/LocalStrings.

chrome/browser/resources/chromeos/network_menu.css

-/* Copyright (c) 2012 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.
- */
-
-input:invalid {
-  background-color: rgb(255, 102, 102);
-}
-
-.left-icon {
-  background-position: 4px top !important;
-}
-
-.network-menu-item {
-  width: 100%;
-}
-
-.network-label-icon {
-  -webkit-box-align: center;
-  display: -webkit-box;
-  min-height: 24px;
-}
-
-.network-label {
-  -webkit-box-flex: 1;
-}
-
-.network-icon {
-  background-position: 50% 50%;
-  background-repeat: no-repeat;
-  height: 24px;
-  width: 24px;
-}
-
-.network-status {
-  color: grey;
-}
-
-.spinner {
-  -webkit-animation-duration: 2s;
-  -webkit-animation-iteration-count: infinite;
-  -webkit-animation-name: spin;
-  -webkit-animation-timing-function: linear;
-  background-image: -webkit-canvas(spinner-circle);
-}
-
-@-webkit-keyframes spin {
-  from {
-    -webkit-transform: rotate(0);
-  }
-  to {
-    -webkit-transform: rotate(360deg);
-  }
-}