Dynamic resize of display rectangles.

chrome/browser/resources/options/chromeos/display_options.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. */
 
 #display-options-page {
   background-color: rgb(240, 240, 240);
 }
 
 #display-options-content-area {
   padding: 0;
 }
 
 #display-options-displays-view-host {
   padding: 20px 0 20px 0;
 }
 
 #display-options-displays-view {
+  overflow: hidden;
   position: relative;
   width: 100%;
 }
 
 #display-options-displays-view-mirroring {
   margin: 20px 0 20px 0;
 }
 
 #display-configurations {
   background-color: white;
@@ skipping 66 matching lines @@
   color: rgb(0, 138, 255);
 }
 
 .display-options-single-button-container {
   margin: 5px 0 5px 0;
 }
 
 .display-options-button {
   width: 120px;
 }