MD Settings: Fix case where 'REMOVE ALL SHOWN' button is erroneously shown.

chrome/browser/resources/settings/site_settings/site_data.html

Index: chrome/browser/resources/settings/site_settings/site_data.html
diff --git a/chrome/browser/resources/settings/site_settings/site_data.html b/chrome/browser/resources/settings/site_settings/site_data.html
index 67cf04a1bda537791b2d4e1981aa8b21f0d91191..f046c297c9a408d055b8a73af5db0578aa039b69 100644
--- a/chrome/browser/resources/settings/site_settings/site_data.html
+++ b/chrome/browser/resources/settings/site_settings/site_data.html
@@ -46,7 +46,8 @@
     </div>
     <div class="list-frame vertical-list">
       <template is="dom-repeat" id="list" items="[[sites]]" filter="showItem_"
-          rendered-item-count="{{renderedItemCount}}">
+          rendered-item-count="{{renderedItemCount::dom-change}}"

[dschuyler, 2017/03/28 19:18:23]

Will this trigger/update more often than it did before, and/or is that likely to
be an issue? My concern is that dom-change may be spammy and this may slow
things down. If it's the same or better (or if there is no feasible alternative)
then this would be ok.

+          notify-dom-change>
         <div class="list-item two-line" on-tap="onSiteTap_" actionable>
           <div class="favicon-image" style$="[[computeSiteIcon(item.site)]]">
           </div>