Unified icon-buttons used in the new GAIA flow.

chrome/browser/resources/chromeos/login/offline_gaia.html

 <link rel="import" href="chrome://resources/polymer/polymer/polymer.html">
 <link rel="import" href="chrome://resources/polymer/polymer/layout.html">
 <link rel="import" href="chrome://resources/polymer/core-animated-pages/core-animated-pages.html">
 <link rel="import" href="chrome://resources/polymer/core-animated-pages/transitions/slide-from-right.html">
 <link rel="import" href="chrome://resources/polymer/paper-button/paper-button.html">
 <link rel="import" href="chrome://resources/polymer/paper-dialog/paper-action-dialog.html">
 
 <!--
   Offline UI for the New Gaia flow.
   Contains two cards with a slide transition between them:
@@ skipping 19 matching lines @@
     'focus' - focuses current screen (email input or password input);
     'setEmail' - accepts an argument |email|. If |email| is empty it sets
                  current screen to the email input, otherwise it sets current
                  screen to password input and shows error that previously
                  entered password is incorrect.
 -->
 <polymer-element name="offline-gaia" vertical layout
     attributes="enterpriseInfo emailDomain">
   <template>
     <link rel="stylesheet" href="offline_gaia.css">
-    <gaia-core-icon-button id="backButton" icon="arrow-back"
-        on-tap="{{onBack}}">
-    </gaia-core-icon-button>
     <core-animated-pages id="animatedPages" transitions="slide-from-right"
         valueattr="id"
         on-core-animated-pages-transition-end="{{onTransitionEnd}}" flex>
       <section flex id="emailSection">
         <gaia-card>
           <div class="header" flex vertical layout end-justified start>
             <h1 class="welcome-message" i18n-content="offlineLoginWelcome"></h1>
             <p class="enterprise-info"  hidden?="{{!enterpriseInfo}}">
               {{enterpriseInfo}}
             </p>
@@ skipping 31 matching lines @@
                 backdrop on-keydown="{{onKeyDownOnDialog}}">
               <p i18n-content="offlineLoginForgotPasswordDlg"></p>
               <gaia-paper-button id="dialogCloseBtn" affirmative autofocus
                   i18n-content="offlineLoginCloseBtn">
               </gaia-paper-button>
             </paper-action-dialog>
           </gaia-input-form>
         </gaia-card>
       </section>
     </core-animated-pages>
+    <button id="backButton" is="gaia-icon-button" icon="arrow-back"
+        i18n-values="aria-label:backButton" on-click="{{onBack}}">
+    </button>
   </template>
 </polymer-element>