Make the minimum progress bar state a rounded dot.

chrome/browser/resources/file_manager/css/common.css

 /* 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. */
 
 /* This file contains "borrowed" copy of standard styles. To simplify merging,
  * when altering, please preserve original property value by adding comments. */
 input.common[type='checkbox'],
 input.common[type='radio'] {
   -webkit-appearance: none;
   border: 1px solid #555;
@@ skipping 518 matching lines @@
 body[new-ui] .progress-bar {
   background-color: #e6e6e6;
   border-radius: 3px;
   height: 6px;
 }
 
 body[new-ui] .progress-track {
   background-color: #888;
   border-radius: 3px;
   height: 6px;
+  min-width: 6px;
 }
 
 .progress-track.smoothed {
   transition: width 1s linear;
 }
 
 /* Icons for the action choice dialog and choosing the default app. */
 div.import-photos-to-drive-icon {
   background-image: -webkit-image-set(
     url('../images/media/drive.png') 1x,
@@ skipping 152 matching lines @@
   width: 44px;
 }
 
 body[new-ui] .cr-dialog-close:hover {
   background-image: url('chrome://theme/IDR_CLOSE_DIALOG_H');
 }
 
 body[new-ui] .cr-dialog-close:active {
   background-image: url('chrome://theme/IDR_CLOSE_DIALOG_P');
 }