Tweaks for improving file manager performance

chrome/browser/resources/shared/js/cr/ui/table/table_header.js

 // Copyright (c) 2012 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 This implements a table header.
  */
 
 cr.define('cr.ui.table', function() {
   const TableSplitter = cr.ui.TableSplitter;
@@ skipping 50 matching lines @@
       var splitters = this.querySelectorAll('.table-header-splitter');
       var rtl = this.ownerDocument.defaultView.getComputedStyle(this)
           .direction == 'rtl';
       for (var i = 0; i < cm.size - 1; i++) {
         leftPercent += cm.getWidth(i);
         splitters[i].style.left = rtl ?
             100 - leftPercent + '%' : leftPercent + '%';
       }
     },
 
+    batchCount_: 0,
+
+    startBatchUpdates: function() {
+      this.batchCount_++;
+    },
+
+    endBatchUpdates: function() {
+      this.batchCount_--;
+      if (this.batchCount_ == 0)
+        this.redraw();
+    },
+
     /**
      * Redraws table header.
      */
     redraw: function() {
+      if (this.batchCount_ != 0)
+        return;
+
       var cm = this.table_.columnModel;
       var dm = this.table_.dataModel;
 
       this.updateWidth();
       this.headerInner_.textContent = '';
 
       if (!cm || ! dm) {
         return;
       }
 
@@ skipping 76 matching lines @@
   /**
    * The table associated with the header.
    * @type {cr.ui.Table}
    */
   cr.defineProperty(TableHeader, 'table');
 
   return {
     TableHeader: TableHeader
   };
 });