Add window buttons (close and maximize) to the Files.app's new UI.

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;
   -webkit-border-radius: 1px;
@@ skipping 396 matching lines @@
 }
 
 body[new-ui] button,
 body[new-ui] input[type='button'],
 body[new-ui] input[type='submit'],
 body[new-ui] select {
   -webkit-border-radius: 2px;
   -webkit-box-shadow: inset 0 1px 1px 0 rgb(255, 255, 255);
   background-color: rgb(250, 250, 250);
   background-image: none;
+  background-position: center;
+  background-repeat: no-repeat;
   border: 1px solid rgb(255, 255, 255);
   border-bottom: 1px solid rgb(180, 180, 180);
   border-left: 1px solid rgb(220, 220, 220);
   border-right: 1px solid rgb(200, 200, 200);
   border-top: 1px solid rgb(220, 220, 220);
   box-sizing: content-box;
   color: rgb(34, 34, 34);
   cursor: default;
   line-height: 27px;
   margin: 0;
@@ skipping 13 matching lines @@
   background: #ebebeb -webkit-linear-gradient(#fefefe, #f8f8f8 40%, #e9e9e9);
   border-color: #999;
   color: #222;
 }
 
 body[new-ui] button:hover,
 body[new-ui] input[type='button']:hover,
 body[new-ui] input[type='submit']:hover,
 body[new-ui] select:hover {
   -webkit-box-shadow: 0 1px 2px rgba(0, 0, 0, 0.1);
-  background: #ebebeb -webkit-linear-gradient(#fefefe, #f8f8f8 40%, #f0f0f0);
+  background-color: #ebebeb;
+  background-image: -webkit-linear-gradient(#fefefe, #f8f8f8 40%, #f0f0f0);
   border-color: rgb(190, 190, 190);
   color: #222;
 }
 
 body:not([new-ui]) button:active,
 body:not([new-ui]) input[type='button']:active,
 body:not([new-ui]) input[type='submit']:active {
   -webkit-box-shadow: inset 0 1px 2px rgba(0, 0, 0, 0.1);
-  background: #ebebeb -webkit-linear-gradient(#f4f4f4, #efefef 40%, #dcdcdc);
+  background-color: #ebebeb;
+  background-image: -webkit-linear-gradient(#f4f4f4, #efefef 40%, #dcdcdc);
   color: #333;
 }
 
 body[new-ui] button:active,
 body[new-ui] input[type='button']:active,
 body[new-ui] input[type='submit']:active {
   -webkit-box-shadow: inset 0 1px 2px rgba(0, 0, 0, 0.1);
-  background: #ebebeb -webkit-linear-gradient(#f4f4f4, #efefef 40%, #dcdcdc);
+  background-color: #ebebeb;
+  background-image: -webkit-linear-gradient(#f4f4f4, #efefef 40%, #dcdcdc);
   color: #333;
 }
 
 body:not([new-ui]) button[disabled],
 body:not([new-ui]) input[type='button'][disabled],
 body:not([new-ui]) input[type='submit'][disabled],
 body:not([new-ui]) button[disabled]:hover,
 body:not([new-ui]) input[type='button'][disabled]:hover,
 body:not([new-ui]) input[type='submit'][disabled]:hover {
   -webkit-box-shadow: none;
@@ skipping 212 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');
 }