Remove app name from File.app's window.

ui/file_manager/file_manager/foreground/css/file_manager.css

 /* Copyright (c) 2014 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. */
 
 /* The order of z-index:
  * - -1: text-measure
  * - 2: drag-selection-border
  * - 3: preview-panel
  * - 500: scrollbar
  * - 500: splitter
@@ skipping 126 matching lines @@
   display: flex;
   flex: none;
   flex-direction: column;
   max-width: 40%;
   min-width: 100px;
   overflow: hidden;
   position: relative;
   width: 190px;
 }
 
-.dialog-navigation-list-header {
-  flex: none;
-  height: 48px;  /* Keep in sync with #dialog-header. */
-  line-height: 45px;
-}
-
-.dialog-navigation-list-header #app-name {
-  color: #303030;
-  font-size: 130%;
-  margin: 0 15px;
-}
-
 .dialog-navigation-list-contents {
   display: flex;
   flex: 1 1 auto;
   position: relative;
 }
 
 .dialog-navigation-list-footer {
   display: flex;
   flex: none;
   flex-direction: column;
@@ skipping 1713 matching lines @@
   visibility: hidden;
 }
 
 .text-measure {
   pointer-events: none;
   position: absolute;
   top: 0;
   visibility: hidden;
   z-index: -1;
 }