Supervised user interstitial: Small style changes.

chrome/browser/resources/supervised_user_block_interstitial.css

 /* Copyright 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. */
 body {
   background-color: rgb(230, 230, 230);
   font-family: Helvetica, Arial, sans-serif;
   font-size: 10pt;
   margin: 50px 40px 20px 40px;
   text-align: center;
 }
@@ skipping 10 matching lines @@
   border-bottom: 1px solid rgb(136, 136, 136);
   border-radius: 3px;
   box-shadow: 0 2px 2px rgb(170, 170, 170);
   color: black;
 }
 
 h1 {
   color: rgb(102, 102, 102);
   font-size: 1.3em;
   font-weight: normal;
-  margin: 5px 0 30px 0;
+  margin: 5px 0 25px 0;
 }
 
 a {
   color: rgb(17, 85, 204);
   text-decoration: none;
 }
 
 .error-img {
   /* Can't access chrome:// urls from an untrusted renderer process, so embed
    * the resource manually. */
@@ skipping 26 matching lines @@
   -webkit-user-select: none;
   background-image: linear-gradient(rgb(246, 246, 246) 5%,
                                     rgb(239, 239, 239) 50%,
                                     rgb(221, 221, 221));
   border: 1px solid rgb(209, 209, 211);
   border-bottom: 1px solid rgb(193, 193, 195);
   border-radius: 2px;
   box-shadow: inset 0 1px 0 rgb(255, 255, 255);
   color: rgb(102, 102, 102);
   font-weight: bold;
-  margin: 5px 0;
+  margin: 5px 3px;
   padding: 8px 13px;
   text-shadow: 0 1px 0 rgba(255, 255, 255, 0.8);
 }
 
-#back-button {
-  background-image: linear-gradient(rgb(84, 153, 244) 5%,
-                                    rgb(82, 148, 242) 50%,
-                                    rgb(75, 133, 241));
-  border: 1px solid rgb(81, 135, 223);
-  border-bottom: 1px solid rgb(56, 112, 207);
-  box-shadow: inset 0 1px 0 rgb(95, 168, 247);
-  color: rgb(255, 255, 255);
-  text-shadow: 0 1px 0 rgba(0, 0, 0, 0.2);
-}
-
 @media (min-width: 376px) {
   #back-button {
     width: 100px;
   }
 }
 
 @media (max-width: 375px) {
   button {
     width: 100%;
   }
 }