Settings: Fix a few overlays that set min-width on the list directly.

chrome/browser/resources/options2/startup_overlay.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. */
 
 #startup-overlay {
-  min-width: 600px;
+  min-width: 500px;
 }
 
 #startupPagesList {
   margin-bottom: 20px;
   min-height: 64px;
-  min-width: 600px;
 }
 
 #startupPagesList .title {
   width: 40%;
 }
 
 #startupPagesList .url {
   -webkit-box-flex: 1;
   color: #666;
 }
@@ skipping 10 matching lines @@
   border-radius: 0;
   border-top-color: transparent;
   box-sizing: border-box;
   display: none;
   height: 6px;
   overflow: hidden;
   pointer-events: none;
   position: fixed;
   z-index: 10;
 }