Implementing Win 10 FRE visual design tweaks requested by first UX pass.

chrome/browser/resources/welcome/win10/sectioned.css

 /* Copyright 2016 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 {
   box-sizing: border-box;
   color: var(--paper-grey-900);
   display: flex;
   flex-direction: column;
   font-size: 100%;
@@ skipping 14 matching lines @@
 
 strong {
   font-weight: 500;
 }
 
 .content {
   padding: 64px 24px 24px 24px;
 }
 
 .header-logo {
-  content: -webkit-image-set(url(/logo-large.png) 1x,
-                             url(/logo-large2x.png) 2x);
+  content: url(chrome://welcome-win10/logo-large.png);
+  height: 4em;
 }
 
 .text {
   margin: 0 auto;
   max-width: 45em;
 }
 
 .heading {
   font-size: 2.125em;
   margin-bottom: .25em;
   margin-top: 1.5em;
 }
 
 .subheading {
   color: var(--google-grey-500);
   font-size: 1em;
   margin-bottom: 1.5em;
   margin-top: .25em;
   text-align: center;
 }
 
 .sections {
-  margin-bottom: 3em;
+  margin-bottom: 2em;
 }
 
 .section.expandable {
   border-top: 1px solid var(--google-grey-300);
 }
 
 .section.expandable:last-child {
   border-bottom: 1px solid var(--google-grey-300);
 }
 
@@ skipping 55 matching lines @@
 
 .section.expandable.expanded .section-steps {
   max-height: 8.75em;
   opacity: 1;
   transition: max-height 300ms cubic-bezier(.4, .2, 0, 1) 50ms,
               opacity 150ms 250ms;
 }
 
 .button {
   -webkit-font-smoothing: antialiased;
-  background: var(--paper-blue-a200);
+  background: var(--google-blue-500);
   border-radius: 2px;
   box-shadow: inset 0 0 0 1px rgba(0, 0, 0, .1);
   color: #fff;
   display: inline-block;
-  font-size: .74em;
+  font-size: .8125em;
   font-weight: 500;
-  line-height: 1.75em;
-  min-width: 2em;
+  line-height: 2.25rem;
   padding: 0 1em;
   text-align: center;
   transition: 300ms cubic-bezier(.4, .2, 0, 1);
   will-change: box-shadow;
 }
 
 .button:hover {
   background: var(--paper-blue-a400);
   box-shadow: inset 0 0 0 1px rgba(0, 0, 0, .1), 0 1px 2px rgba(0, 0, 0, .24);
 }
 
 .bg {
   background: var(--paper-light-blue-700);
   flex: 1;
   margin-top: 96px;
   padding: 24px;
 }
 
 .logo-small {
-  content: -webkit-image-set(url(/logo-small.png) 1x,
-                             url(/logo-small2x.png) 2x);
+  content: url(chrome://welcome-win10/logo-small.png);
   display: inline;
   height: 1.25em;
   vertical-align: top;
   width: 1.25em;
 }
 
 .screenshots {
   display: block;
   height: 440px;
   margin: 0 auto;
@@ skipping 114 matching lines @@
     max-width: 42%;
     padding: 0;
   }
 
   .screenshots {
     margin-left: -180px;
     max-width: none;
     top: 0;
   }
 }