Simplifed logic of showing/hiding cancel buttons on login screens.

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

Index: chrome/browser/resources/chromeos/login/header_bar.js
diff --git a/chrome/browser/resources/chromeos/login/header_bar.js b/chrome/browser/resources/chromeos/login/header_bar.js
index 5a747c8ea7cfb880788a891da168c6f1b13cbd3b..723fa6841152b21acbf27d8979dc0aa33f996422 100644
--- a/chrome/browser/resources/chromeos/login/header_bar.js
+++ b/chrome/browser/resources/chromeos/login/header_bar.js
@@ -54,8 +54,6 @@ cr.define('login', function() {
           this.handleAddUserClick_);
       $('more-settings-button').addEventListener('click',
           this.handleMoreSettingsClick_.bind(this));
-      $('cancel-add-user-button').addEventListener('click',
-          this.handleCancelAddUserClick_);
       $('guest-user-header-bar-item').addEventListener('click',
           this.handleGuestClick_);
       $('guest-user-button').addEventListener('click',
@@ -275,20 +273,6 @@ cr.define('login', function() {
     },
 
     /**
-     * Whether the Cancel button is enabled during Gaia sign-in.
-     *
-     * @type {boolean}
-     */
-    set allowCancel(value) {
-      this.allowCancel_ = value;
-      this.updateUI_();
-    },
-
-    get allowCancel() {
-      return !!this.allowCancel_;
-    },
-
-    /**
      * Update whether there are kiosk apps.
      *
      * @type {boolean}
@@ -342,16 +326,6 @@ cr.define('login', function() {
           isLockScreen ||
           errorScreenIsActive ||
           supervisedUserCreationDialogIsActive;
-      $('cancel-add-user-button').hidden =
-          !this.allowCancel_ ||
-          gaiaIsActive ||
-          isPasswordChangedUI ||
-          isSamlPasswordConfirm ||
-          errorScreenIsActive ||
-          accountPickerIsActive ||
-          wrongHWIDWarningIsActive ||
-          isMultiProfilesUI ||
-          supervisedUserCreationDialogIsActive;
       $('guest-user-header-bar-item').hidden =
           !this.showGuest_ ||
           isLockScreen ||
@@ -359,15 +333,14 @@ cr.define('login', function() {
           wrongHWIDWarningIsActive ||
           isSamlPasswordConfirm ||
           isMultiProfilesUI ||
-          (this.allowCancel_ && gaiaIsActive) ||
+          (gaiaIsActive && $('gaia-signin').cancelable) ||
           enrollmentIsActiveWithBackButton ||
           gaiaIsActiveWithBackButton;
       $('restart-header-bar-item').hidden = !this.showReboot_;
       $('shutdown-header-bar-item').hidden = !this.showShutdown_;
       $('sign-out-user-item').hidden = !isLockScreen;
 
-      $('add-user-header-bar-item').hidden =
-          $('add-user-button').hidden && $('cancel-add-user-button').hidden;
+      $('add-user-header-bar-item').hidden = $('add-user-button').hidden;
       $('apps-header-bar-item').hidden = !this.hasApps_ ||
           (!gaiaIsActive && !accountPickerIsActive);
       $('cancel-multiple-sign-in-item').hidden = !isMultiProfilesUI;