Replace deprecated iron-flex-layout/classes with iron-flex-layout-class in MD Settings

chrome/browser/resources/settings/device_page/display.html

 <link rel="import" href="chrome://resources/html/i18n_behavior.html">
 <link rel="import" href="chrome://resources/html/polymer.html">
-<link rel="import" href="chrome://resources/polymer/v1_0/iron-flex-layout/classes/iron-flex-layout.html">
+<link rel="import" href="chrome://resources/polymer/v1_0/iron-flex-layout/iron-flex-layout-classes.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-button/paper-button.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-checkbox/paper-checkbox.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-dropdown-menu/paper-dropdown-menu.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-listbox/paper-listbox.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-slider/paper-slider.html">
 <link rel="import" href="/device_page/display_layout.html">
 <link rel="import" href="/device_page/display_overscan_dialog.html">
 <link rel="import" href="/settings_shared_css.html">
 
 <dom-module id="settings-display">
   <template>
-    <style include="settings-shared">
+    <style include="iron-flex iron-flex-alignment settings-shared">
      .display-section {
        align-self: flex-start;
        font-size: 100%;
        font-weight: 500;
        margin: 10px 0;
      }
 
      .settings-box.embedded {
        align-self: stretch;
        margin-left: 20px;
@@ skipping 80 matching lines @@
       </div>
 
       <settings-display-overscan-dialog id="displayOverscan"
           display-id="{{overscanDisplayId}}">
       </settings-display-overscan-dialog>
 
     </div>
   </template>
   <script src="display.js"></script>
 </dom-module>