MD History: Add routing for grouped history mode.

chrome/browser/resources/md_history/history_list_behavior.js

Index: chrome/browser/resources/md_history/history_list_behavior.js
diff --git a/chrome/browser/resources/md_history/history_list_behavior.js b/chrome/browser/resources/md_history/history_list_behavior.js
index 3f871c40619d8ebbbc84c893a97c8621e9ab98f0..7de36b90d915afd6355717606743c5e4f3467cea 100644
--- a/chrome/browser/resources/md_history/history_list_behavior.js
+++ b/chrome/browser/resources/md_history/history_list_behavior.js
@@ -30,6 +30,12 @@ SelectionTreeNode.prototype.addChild = function(index, path) {
 var HistoryListBehavior = {
   properties: {
     /**
+     * Allows data to be imported into the list as soon as it is upgraded.
+     * @type {!Array<!HistoryEntry>}
+     */
+    initialData: Array,
+
+    /**
      * Polymer paths to the history items contained in this list.
      * @type {!Set<string>} selectedPaths
      */
@@ -47,6 +53,12 @@ var HistoryListBehavior = {
     'history-checkbox-select': 'itemSelected_',
   },
 
+  /** @override */
+  attached: function() {
+    if (this.initialData)
+      this.addNewResults(this.initialData, false, false);
+  },
+
   /**
    * @param {!Array<!HistoryEntry>} results
    * @param {boolean} incremental True if the results are from an incremental