Add autorefresh_list experiment

This experiment/feature checks at regular intervals whether there are
updates to thread lists, and notifies the user via a snackbar when
an update exists.

Bug: #42
Change-Id: I98e4aa03a7080c6bff781ce7c850477433090957
diff --git a/src/_locales/es/messages.json b/src/_locales/es/messages.json
index 596b5ab..a591db4 100644
--- a/src/_locales/es/messages.json
+++ b/src/_locales/es/messages.json
@@ -103,6 +103,10 @@
     "message": "Muestra fotos de perfil en las listas de hilos de la Consola de la Comunidad.",
     "description": "Feature checkbox in the options page"
   },
+  "options_autorefreshlist": {
+    "message": "Actualiza las listas de hilos de la Consola de la Comunidad automáticamente.",
+    "description": "Feature checkbox in the options page"
+  },
   "options_profileindicator_moreinfo": {
     "message": "+info sobre las 2 opciones anteriores",
     "description": "Link to learn more about the profile indicator feature"
@@ -226,5 +230,13 @@
   "inject_lockdialog_log_entry_error_unlock": {
     "message": "Ha ocurrido un error desbloqueándolo ($1).",
     "description": "Second part of the entry in the log of the 'lock/unlock threads' dialog, when the log entry states that the thread was *not* *un*locked successfully. Log entries are of the form '{first_part}: {second_part}'. For example: 'Thread 164: Locked successfully'."
+  },
+  "inject_autorefresh_list_snackbar_message": {
+    "message": "Hay nuevos hilos.",
+    "description": "Message shown in a snackbar when new threads are found in a thread list. Another button asks the user to refresh the list."
+  },
+  "inject_autorefresh_list_snackbar_action": {
+    "message": "Actualizar",
+    "description": "Button shown in a snackbar asking users to refresh/reload the list to show the new threads."
   }
 }