remove unnecessary paper-item dependency from site_details.

chrome/test/data/webui/settings/site_details_tests.js

Index: chrome/test/data/webui/settings/site_details_tests.js
diff --git a/chrome/test/data/webui/settings/site_details_tests.js b/chrome/test/data/webui/settings/site_details_tests.js
index a4ed1046959b52787bad56272d5860bc16c84821..8e599855b99953f80573e3c6ea456d957412f9fd 100644
--- a/chrome/test/data/webui/settings/site_details_tests.js
+++ b/chrome/test/data/webui/settings/site_details_tests.js
@@ -143,8 +143,8 @@ cr.define('site_details', function() {
         testElement.category = category;
         testElement.site = site
 
-        assertTrue(testElement.$.usage.hidden);
-        assertTrue(testElement.$.storage.hidden);
+        //expect usage to not be rendered

[Dan Beam, 2016/11/18 16:48:07]

I don't think this comment adds much

+        assertFalse(!!testElement.$$('#usage'));
 
         // TODO(finnur): Check for the Permission heading hiding when no
         // permissions are showing.
@@ -205,8 +205,10 @@ cr.define('site_details', function() {
           embeddingOrigin: '',
         };
 
-        assertFalse(testElement.$.usage.hidden);
-        assertFalse(testElement.$.storage.hidden);
+        Polymer.dom.flush();
+
+        //expect usage to be rendered

[Dan Beam, 2016/11/18 16:48:07]

// Expect usage to be rendered.

+        assertTrue(!!testElement.$$('#usage'));
       });
     });
   }