Files.app: Move the position of dummy element for measuring the size of text.

ui/file_manager/file_manager/foreground/css/file_manager.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. */
 
 /* The order of z-index:
+ * - -1: text-measure
  * - 2: drag-selection-border
  * - 3: preview-panel
  * - 500: scrollbar
  * - 500: splitter
  * - 525: spinner
  * - 550: autocomplete-suggestions
  * - 600: menus
  * - 600: tooltip
  * - 1000: preview thumbnail popup
  * - 1000: overlay panel (ie. image editor)
@@ skipping 1941 matching lines @@
   display: none;
 }
 
 #progress-center-close-view.single button.open {
   display: none;
 }
 
 #progress-center li:not(.cancelable) button.cancel {
   visibility: hidden;
 }
+
+.text-measure {
+  pointer-events: none;
+  position: absolute;
+  top: 0;
+  visibility: hidden;
+  z-index: -1;
+}