[MD Bookmarks] Flatten sidebar.

chrome/browser/resources/md_bookmarks/sidebar.js

Index: chrome/browser/resources/md_bookmarks/sidebar.js
diff --git a/chrome/browser/resources/md_bookmarks/sidebar.js b/chrome/browser/resources/md_bookmarks/sidebar.js
index c12acde5da52c58529a660678d369105a3e9c140..91e30f5d55b6a22eabcc179f425a2c624ff31b9c 100644
--- a/chrome/browser/resources/md_bookmarks/sidebar.js
+++ b/chrome/browser/resources/md_bookmarks/sidebar.js
@@ -10,13 +10,17 @@ Polymer({
   ],
 
   properties: {
-    rootFolders: Array,
+    folders: Array,
   },
 
   attached: function() {
-    this.observe('rootFolders', function(store) {
-      return store.nodes['0'].children;
+    this.observe('folders', function(store) {
+      return store.sidebar.folders;
     });
     this.updateFromStore();
   },
+
+  isVisible_: function(folder) {
+    return folder.visible;
+  },
 });