Implement deletion of storage per site.

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

Index: chrome/test/data/webui/settings/site_list_tests.js
diff --git a/chrome/test/data/webui/settings/site_list_tests.js b/chrome/test/data/webui/settings/site_list_tests.js
index 50bc3eaf80ea32cd55012482a2969b040ba049cb..8c18d1ce684edaf24d26088e29473fa36d3f9caf 100644
--- a/chrome/test/data/webui/settings/site_list_tests.js
+++ b/chrome/test/data/webui/settings/site_list_tests.js
@@ -139,6 +139,11 @@ cr.define('site_list', function() {
         testElement.categorySubtype = subtype;
         testElement.categoryEnabled = true;
         testElement.prefs = prefs;
+        testElement.currentRoute = {
+          page: 'dummy',
+          section: 'privacy',
+          subpage: ['site-settings', 'site-settings-category-location'],
+        };
       }
 
       test('Empty list', function() {