Add close button to the supervised user pages.

BUG=487351
TEST=manual

Review URL: https://codereview.chromium.org/1131683004

Cr-Commit-Position: refs/heads/master@{#330231}

chrome/browser/resources/chromeos/login/header_bar.js

@@ -352,7 +352,8 @@ cr.define('login', function() {
           accountPickerIsActive ||
           !this.allowCancel_ ||
           wrongHWIDWarningIsActive ||
-          isMultiProfilesUI;
+          isMultiProfilesUI ||
+          supervisedUserCreationDialogIsActive;
       $('guest-user-header-bar-item').hidden =
           (gaiaIsActive && !this.isNewGaiaFlow_) ||
           supervisedUserCreationDialogIsActiveAndNotIntro ||

chrome/browser/resources/chromeos/login/screen_supervised_user_creation.css

@@ -549,3 +549,16 @@ html[dir=rtl] #supervised-user-creation-flip-photo {
 .camera.live:not(.online) .supervised-user-creation-image-stream-area .spinner {
   display: block;
 }
+
+#supervised-user-creation-close-button-item {
+  color: rgba(0, 0, 0, .54);
+  position: absolute;
+  right: 10px;
+  top: 10px;
+  z-index: 1;
+}
+
+html[dir=rtl] #supervised-user-creation-close-button-item {
+  left: 10px;
+  right: auto;
+}

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

+<link rel="import" href="chrome://oobe/custom_elements.html">
 <div class="step hidden" id="supervised-user-creation" hidden>
   <div class="step-contents">
     <div id="supervised-user-creation-intro" class="step-no-logo">
@@ -157,4 +158,7 @@
     <img class="import-pod-image"></img>
     <div class="import-pod-name"></div>
   </div>
+  <button id="supervised-user-creation-close-button-item" is="gaia-icon-button"
+      icon="close" i18n-values="aria-label:closeButton" tabindex="0">
+  </button>
 </div>

chrome/browser/resources/chromeos/login/screen_supervised_user_creation.js

@@ -616,6 +616,12 @@ login.createScreen('SupervisedUserCreationScreen',
           'webkitTransitionEnd', function(e) {
             previewElement.classList.remove('animation');
           });
+
+      $('supervised-user-creation-close-button-item').addEventListener(
+          'click', function(e) {
+            this.cancel();
+            e.preventDefault();
+          }.bind(this));
     },
 
     buttonIds: [],
@@ -1193,6 +1199,9 @@ login.createScreen('SupervisedUserCreationScreen',
             !this.importList_.selectedPod_ ||
             this.importList_.selectedPod_.user.exists;
       }
+      $('supervised-user-creation-close-button-item').hidden =
+          (visiblePage == 'created');
+
       chrome.send('currentSupervisedUserPage', [this.currentPage_]);
     },