Submit button added to user pod.

ui/login/account_picker/user_pod_row.css

 /* Copyright 2014 The Chromium Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  *
  * This is the stylesheet used by user pods row of account picker UI.
  */
 
 podrow {
   /* Temporarily disabled because animation interferes with updating screen's
    size. */
@@ skipping 143 matching lines @@
   left: auto;
   right: 10px;
 }
 
 .name-container,
 .pod.focused:not(.multiprofiles-policy-applied) .auth-container {
   background-color: white;
   display: flex;
   position: absolute;
   top: 160px;
-  width: 160px;
+  width: 170px;
+}
+
+.auth-container .submit-button[disabled] {
+  color: #000;
+  opacity: 0.26;
+}
+
+.auth-container .submit-button {
+  box-sizing: border-box;
+  color: var(--google-blue-500);
+  height: 43px;
+  min-height: 43px;
+  min-width: 43px;
+  padding: 11.5px 10px;
+  position: relative;
+  width: 43px;
+}
+
+.auth-container .submit-button.error-shown {
+  color: #CD2A00;
 }
 
 .name-container {
   transition: transform 180ms,
               opacity 180ms ease-in-out 180ms,
               visibility 180ms ease-in-out 180ms;
   opacity : 1;
   visibility: visible;
 }
 
@@ skipping 47 matching lines @@
   width: 100%;
 }
 
 .capslock-hint-container {
   display: none;
 }
 
 .capslock-on .capslock-hint-container {
   display: block;
   flex: none;
+  height: 43px;
+  position: relative;
+  width: 20px;
 }
 
 .capslock-hint {
   -webkit-margin-end: 6px;
   -webkit-margin-start: -2px;
+  margin: auto;
   position: relative;
-  top: 11px;
+  top: 15px;
 }
 
 .password-label,
 .signin-transition-container {
   display: none;
 }
 
 .pod[auth-type='userClick']:not(.signing-in) .password-label,
 .pod[auth-type='userClick'].signing-in .signin-transition-container {
   color: grey;
@@ skipping 614 matching lines @@
   -webkit-animation: ellipsis-component2 1.5s infinite;
 }
 
 @-webkit-keyframes ellipsis-component2 {
   0% { opacity: 0; }
   25% { opacity: 0; }
   50% { opacity: 0; }
   75% { opacity: 1; }
   100% { opacity: 0; }
 }