Make lists in the passwords section aware of the scroll target.

chrome/browser/resources/settings/settings_main/settings_main.js

Index: chrome/browser/resources/settings/settings_main/settings_main.js
diff --git a/chrome/browser/resources/settings/settings_main/settings_main.js b/chrome/browser/resources/settings/settings_main/settings_main.js
index f931e6f0d5ada17b21a893cb1242ba9c06c49eea..936e9e6478a1816e857cfe13696e3d2e847a02a3 100644
--- a/chrome/browser/resources/settings/settings_main/settings_main.js
+++ b/chrome/browser/resources/settings/settings_main/settings_main.js
@@ -86,6 +86,12 @@ Polymer({
       type: Object,
       value: function() { return {}; },
     },
+
+    /**
+     * The scroll target for the lists in this section.
+     * @type {Element}
+     */
+    scrollTarget: HTMLElement,
   },
 
   /** @override */