[Resources] Move roboto.woff and add roboto.woff2 to a roboto/ directory

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: 'Roboto';
+  font-family: 'Roboto2';
   font-weight: 400;
-  src: url(/roboto.woff) format('woff');
+  src: local('Roboto'), local('Roboto2-Regular'),
+      url(/roboto.woff2) format('woff2'), url(/roboto.woff) format('woff');
 }
 
 body {
-  font-family: 'Roboto';
+  font-family: 'Roboto2', sans-serif;
   font-size: 1em;
   margin: 0;
 }
 
 p {
   margin: 1.5em;
   text-align: justify;
 }
 
 a {
@@ skipping 15 matching lines @@
   text-decoration: none;
   text-transform: uppercase;
 }
 
 #button-container {
   position: fixed;
   text-align: right;
   top: calc(70% - 76px /* action bar */ - 69px /* height of content */);
   width: 100%;
 }