Revert of [i18n] chromeos login i18n-content to $i18n{}

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

 <link rel="import" href="chrome://resources/polymer/v1_0/polymer/polymer.html">
 
 <!--
 UI for the SAML interstitial page.
 Example:
   <saml-interstitial></saml-interstitial>
 
 Attributes:
   'domain' - The enterprise domain the device is enrolled to.
   'showDomainMessages' - If true, the messages showing the enrollment domain
@@ skipping 21 matching lines @@
   <style>
     :host {
       display: block;
       line-height: 150%;
     }
   </style>
 
   <gaia-card id="samlInterstitialCard" class="fit">
     <div id="samlInterstitialHeader"
         class="header flex vertical layout end-justified start">
-      <h1 class="welcome-message">$i18n{loginWelcomeMessage}</h1>
+      <h1 class="welcome-message" i18n-content="loginWelcomeMessage">
+      </h1>
       <p id="managedBy" class="enterprise-info"
          hidden$="[[!showDomainMessages_]]">
       </p>
     </div>
 
     <div class="footer flex vertical layout justified">
       <!-- This message contains a <strong> tag inside. -->
       <html-echo id="message" hidden$="[[!showDomainMessages_]]"></html-echo>
 
       <gaia-input-form id="samlInterstitialForm"
                        on-submit="onSamlPageNextClicked_"
                        i18n-values="button-text:samlInterstitialNextBtn">
         <gaia-button id="changeAccountLink" type="link"
-            on-tap="onSamlPageChangeAccountClicked_">
-          $i18n{samlInterstitialChangeAccountLink}
+                     on-tap="onSamlPageChangeAccountClicked_"
+                     i18n-content="samlInterstitialChangeAccountLink">
         </gaia-button>
       </gaia-input-form>
 
       <img id="logo-img" src="chrome://theme/IDR_LOGO_GOOGLE_COLOR_90"
            class="self-center" alt="">
     </div>
   </gaia-card>
 
 </template>
 
 </dom-module>