Add empty list indicator for Physical Web WebUI

components/physical_web/webui/resources/physical_web.css

Index: components/physical_web/webui/resources/physical_web.css
diff --git a/components/physical_web/webui/resources/physical_web.css b/components/physical_web/webui/resources/physical_web.css
index 29298209538c5c693104ecb6fa0b2ad1edac560b..408340b63f604b12d815a32057707c5b4b6930f6 100644
--- a/components/physical_web/webui/resources/physical_web.css
+++ b/components/physical_web/webui/resources/physical_web.css
@@ -50,3 +50,11 @@ body {
   overflow: hidden;
   text-overflow: ellipsis;
 }
+
+#body-container {
+  visibility:visible;

[cco3, 2017/02/23 23:36:54]

This is default, so I don't think it's needed.

[Ran, 2017/02/24 18:52:59]

Done.

+}
+
+#empty-container {
+  visibility:hidden;

[cco3, 2017/02/23 23:36:54]

I think we should be using display:none, because otherwise this will take up
space you shouldn't be taking up.

[Ran, 2017/02/24 18:52:59]

Done.

+}