Implement md-settings network lists.

ui/webui/resources/cr_elements/cr_network_list/cr_network_list.css

Index: ui/webui/resources/cr_elements/cr_network_list/cr_network_list.css
diff --git a/ui/webui/resources/cr_elements/cr_network_list/cr_network_list.css b/ui/webui/resources/cr_elements/cr_network_list/cr_network_list.css
new file mode 100644
index 0000000000000000000000000000000000000000..b4d5de05e8f90a73b996872ab9b6efb4292a1f34
--- /dev/null
+++ b/ui/webui/resources/cr_elements/cr_network_list/cr_network_list.css
@@ -0,0 +1,15 @@
+/* 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. */
+
+#container {
+  border: 1px solid;
+  max-height: 1000px;
+  min-height: 50px;
+  overflow-y: auto;
+}
+
+/* Note: the 'flex' attribute on core-list doesn't work as expected. */
+#networkList {
+  flex: 1;
+}