Submit button added to user pod.

ui/login/account_picker/user_pod_template.html

 <dom-module id="user-pod-template-shared-styles">
   <template>
     <link rel="stylesheet" href="user_pod_template.css">
   </template>
 </dom-module>
 
 <style is="custom-style" include="user-pod-template-shared-styles"></style>
 
+<iron-iconset-svg name="user-pod" size="24">
+  <svg>
+    <defs>
+      <!--
+      Inlined from Polymer's iron-icons to avoid importing everything.
+      See http://goo.gl/Y1OdAq for instructions on adding additional icons.
+      -->
+      <g id="arrow-forward"><path d="M12 4l-1.41 1.41L16.17 11H4v2h12.17l-5.58 5.59L12 20l8-8z"/></g>
+    </defs>
+  </svg>
+</iron-iconset-svg>
+
 <div id="user-pod-template" class="pod disabled" hidden>
   <div class="user-image-pane">
     <div class="user-image-container">
       <img class="user-image" alt>
     </div>
     <div class="signed-in-indicator" i18n-content="signedIn"></div>
     <div class="indicator-container">
       <div class="indicator legacy-supervised-indicator"></div>
       <div class="indicator child-indicator"></div>
       <div class="indicator locked-indicator"></div>
     </div>
   </div>
 <if expr="chromeos">
   <div class="pin-container pin-disabled pin-tag">
     <pin-keyboard enable-password hide-input></pin-keyboard>
   </div>
 </if>
   <div class="main-pane">
     <div class="name-container pin-tag">
       <div class="name"></div>
       <div class="learn-more-container">
         <div class="learn-more"></div>
       </div>
     </div>
-    <div class="auth-container pin-tag">
+    <div class="auth-container">
       <!-- Password Authentication -->
       <div class="password-entry-container">
         <div class="password-container">
           <input type="password" class="password"
                  i18n-values="placeholder:passwordHint">
         </div>
         <div class="capslock-hint-container">
           <img class="capslock-hint"
                src="chrome://theme/IDR_LOGIN_PASSWORD_CAPS_LOCK" alt>
         </div>
+        <paper-icon-button class="submit-button" disabled
+                           icon="user-pod:arrow-forward">
+        </paper-icon-button>
       </div>
       <!-- User Click Authentication -->
       <div class="password-label"></div>
       <div class="signin-transition-container">
         <span class="signing-in-label" i18n-content="signingIn"></span>
         <span class="animated-ellipsis-component0">.</span>
         <span class="animated-ellipsis-component1">.</span>
         <span class="animated-ellipsis-component2">.</span>
       </div>
       <div class="custom-icon-container" hidden></div>
@@ skipping 119 matching lines @@
              i18n-content="publicSessionLanguageAndInput"></a>
         </div>
         <button class="enter-button"
                 i18n-content="publicAccountEnter"
                 i18n-values="aria-label:publicAccountEnterAccessibleName">
         </button>
       </div>
     </div>
   </div>
 </div>