MDUserManager: import the appropriate dom-modules form iron-flex-layout-classes

chrome/browser/resources/md_user_manager/create_profile.html

 <link rel="import" href="/import_supervised_user.html">
 <link rel="import" href="/profile_browser_proxy.html">
 <link rel="import" href="/shared_styles.html">
 <link rel="import" href="chrome://resources/cr_elements/icons.html">
 <link rel="import" href="chrome://resources/html/action_link.html">
 <link rel="import" href="chrome://resources/html/cr.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/html/util.html">
 <link rel="import" href="chrome://resources/html/web_ui_listener_behavior.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-input/paper-input.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-item/paper-item.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-spinner/paper-spinner.html">
 
 <dom-module id="create-profile">
   <template>
-    <style include="shared-styles">
+    <style include="shared-styles iron-positioning">
       .container {
         color: var(--primary-text-color);
         width: var(--page-width);
       }
 
       #message-container {
         -webkit-transition: top 400ms cubic-bezier(.4, 0, .2, 1),
                             visibility 0s linear 400ms;
         align-items: center;
         background-color: var(--paper-red-50);
@@ skipping 203 matching lines @@
         <paper-button id="save" class="action primary" on-tap="onSaveTap_"
             disabled="[[isSaveDisabled_(createInProgress_, profileName_)]]">
           $i18n{createProfileConfirm}
         </paper-button>
       </div>
       <import-supervised-user id="importUserPopup"></import-supervised-user>
     </div>
   </template>
   <script src="create_profile.js"></script>
 </dom-module>