[Search] Modify the First-run experience in Landscape mode

chrome/browser/resources/contextual_search/promo.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.
 */
 @font-face {
   font-family: 'Roboto2';
   font-weight: 400;
   src: local('Roboto'), local('Roboto2-Regular'),
       url(/roboto.woff2) format('woff2'), url(/roboto.woff) format('woff');
 }
 
 body {
   color: #414141;
   font-family: 'Roboto2', sans-serif;
   margin: 0;
 }
 
 a {
   text-decoration: none;
 }
 
 a.colored-link {
   color: rgb(66, 133, 244);
 }
 
 #button-container {
-  text-align: right;
+  text-align: end;
   width: 100%;
 }
 
 #container.hide {
   -webkit-transform: scale(0.95);
   -webkit-transition-duration: 218ms;
   -webkit-transition-property: opacity, -webkit-transform;
   opacity: 0;
 }
 
 #description {
   font-size: 16px;
   line-height: 1.4em;
   margin: 24px 16px 4px 16px;
 }
 
+/* Some properties below can be overridden in landscape orientation. */
 #heading {
   font-size: 24px;
   letter-spacing: 1px;
   margin-top: 0;
   text-align: center;
 }
-
 #header-image {
-  display: block;
   height: 100px;
   margin: 0 auto 24px auto;
 }
+.portrait {
+  display: block;
+}
+.landscape {
+  display: none;
+}
+
+/* Landscape */
+@media screen and (orientation:landscape) {
+  #heading {
+    padding-top: 16px;
+  }
+  #header-image {
+    margin: 0 24px;
+  }
+  .portrait {
+    display: none;
+  }
+  .landscape {
+    display: block;
+    float: left;
+  }
+  html[dir='rtl'] .landscape {
+    float: right;
+  }
+}
 
 .label {
   display: inline-block;
   font-size: 14px;
   margin: 14px 0;
   /* We use a slightly different top-bottom padding because Roboto has a
      rendering bug which makes an extra padding to be rendered at the bottom of
      text. */
   padding: 17px 14px 13px 14px;
   white-space: nowrap;
@@ skipping 10 matching lines @@
   margin-right: 24px;
 }
 
 #optin-label a {
   color: white;
 }
 
 #optout-label a {
   color: rgb(66, 133, 244);
 }