Settings: Cookies: Avoid duplicate 'incognito' exceptions in CrOS Guest mode

chrome/browser/resources/settings/site_settings/add_site_dialog.js

Index: chrome/browser/resources/settings/site_settings/add_site_dialog.js
diff --git a/chrome/browser/resources/settings/site_settings/add_site_dialog.js b/chrome/browser/resources/settings/site_settings/add_site_dialog.js
index 09263f15c9151a02e78bbebd3d344f5e0718764c..91ceb616f6f8e0a582c5dedc387c6b20a8045efd 100644
--- a/chrome/browser/resources/settings/site_settings/add_site_dialog.js
+++ b/chrome/browser/resources/settings/site_settings/add_site_dialog.js
@@ -46,6 +46,7 @@ Polymer({
     this.addWebUIListener('onIncognitoStatusChanged', function(hasIncognito) {
       this.$.incognito.checked = false;
       this.showIncognitoSessionOnly_ = hasIncognito &&
+          !loadTimeData.getBoolean('isGuest') &&
           this.contentSetting != settings.PermissionValues.SESSION_ONLY;
     }.bind(this));
     this.browserProxy.updateIncognitoStatus();