MD Bookmarks: Prevent flash of folder contents when changing search term

chrome/browser/resources/md_bookmarks/util.js

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * @fileoverview Utility functions for the Bookmarks page.
  */
 
 cr.define('bookmarks.util', function() {
   /**
    * Returns the list of bookmark IDs to be displayed in the UI, taking into
    * account search and the currently selected folder.
    * @param {!BookmarksPageState} state
    * @return {!Array<string>}
    */
   function getDisplayedList(state) {
-    if (!isShowingSearch(state))
-      return assert(state.nodes[state.selectedFolder].children);
+    if (isShowingSearch(state))
+      return assert(state.search.results);
 
-    return state.search.results;
+    return assert(state.nodes[state.selectedFolder].children);
   }
 
   /**
    * @param {BookmarkTreeNode} treeNode
    * @return {BookmarkNode}
    */
   function normalizeNode(treeNode) {
     var node = Object.assign({}, treeNode);
     // Node index is not necessary and not kept up-to-date. Remove it from the
     // data structure so we don't accidentally depend on the incorrect
@@ skipping 39 matching lines @@
       nodes: {},
       selectedFolder: BOOKMARKS_BAR_ID,
       closedFolders: new Set(),
       prefs: {
         canEdit: true,
         incognitoAvailability: IncognitoAvailability.ENABLED,
       },
       search: {
         term: '',
         inProgress: false,
-        results: [],
+        results: null,
       },
       selection: {
         items: new Set(),
         anchor: null,
       },
     };
   }
 
   /**
    * @param {BookmarksPageState} state
    * @return {boolean}
    */
   function isShowingSearch(state) {
-    return !!state.search.term && !state.search.inProgress;
+    return state.search.results != null;
   }
 
   /**
    * Returns true if the node with ID |itemId| is modifiable, allowing
    * the node to be renamed, moved or deleted. Note that if a node is
    * uneditable, it may still have editable children (for example, the top-level
    * folders).
    * @param {BookmarksPageState} state
    * @param {string} itemId
    * @return {boolean}
@@ skipping 95 matching lines @@
     getDescendants: getDescendants,
     getDisplayedList: getDisplayedList,
     hasChildFolders: hasChildFolders,
     isShowingSearch: isShowingSearch,
     normalizeNode: normalizeNode,
     normalizeNodes: normalizeNodes,
     removeIdsFromMap: removeIdsFromMap,
     removeIdsFromSet: removeIdsFromSet,
   };
 });