Add support for custom entries in <cr_network_select/>.

ui/webui/resources/cr_elements/network/cr_network_list.js

Index: ui/webui/resources/cr_elements/network/cr_network_list.js
diff --git a/ui/webui/resources/cr_elements/network/cr_network_list.js b/ui/webui/resources/cr_elements/network/cr_network_list.js
index 24178c4e6c44876aa877cba11facde124c8980f8..398c8622a588d263e525ae37e0f476ddc65d779d 100644
--- a/ui/webui/resources/cr_elements/network/cr_network_list.js
+++ b/ui/webui/resources/cr_elements/network/cr_network_list.js
@@ -38,6 +38,7 @@ Polymer({
 
     /**
      * The list of network state properties for the items to display.
+     * See <cr-network-list-network-item/> for details.
      *
      * @type {!Array<!CrOnc.NetworkStateProperties>}
      */
@@ -47,12 +48,31 @@ Polymer({
     },
 
     /**
+     * The list of custom state properties for the items to display.
+     * See <cr-network-list-custom-item/> for details.
+     *
+     * @type {!Array<Object>}
+     */
+    customItems: {
+      type: Array,
+      value: function() { return []; }
+    },
+
+    /**
      * True if the list is opened.
      */
     opened: {
       type: Boolean,
       value: true
-    }
+    },
+
+    /**
+     * Shows all buttons from the list items.
+     */
+    showButtons: {
+      type: Boolean,
+      value: false,
+    },
   },
 
   /**