Disable SSO option for MGS on file share UI

Since Kerberos support was added to managed guest sessions (MGS), the
SSO option became available on "add file share" service. This CL removes
this option from the UI, because this service is not working properly on
MGS. See corresponding bug for additional information.

Bug: 1186188
Change-Id: I2a70861ce06f2f764684a22025cfcdb983fd8131
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2743482
Commit-Queue: Felipe Andrade <fsandrade@chromium.org>
Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Reviewed-by: Josh Simmons <simmonsjosh@google.com>
Cr-Commit-Position: refs/heads/master@{#861709}

chrome/browser/ui/webui/chromeos/smb_shares/smb_share_dialog.cc

@@ -14,6 +14,7 @@
 #include "chrome/grit/browser_resources.h"
 #include "chrome/grit/generated_resources.h"
 #include "components/strings/grit/components_strings.h"
+#include "components/user_manager/user_manager.h"
 #include "content/public/browser/web_ui.h"
 #include "content/public/browser/web_ui_data_source.h"
 
@@ -86,6 +87,10 @@ SmbShareDialogUI::SmbShareDialogUI(content::WebUI* web_ui)
       smb_service && smb_service->IsKerberosEnabledViaPolicy();
   source->AddBoolean("isKerberosEnabled", is_kerberos_enabled);
 
+  bool is_guest = user_manager::UserManager::Get()->IsLoggedInAsGuest() ||
+                  user_manager::UserManager::Get()->IsLoggedInAsPublicAccount();
+  source->AddBoolean("isGuest", is_guest);
+
   source->UseStringsJs();
   source->SetDefaultResource(IDR_SMB_SHARES_DIALOG_CONTAINER_HTML);
   source->AddResourcePath("smb_share_dialog.js", IDR_SMB_SHARES_DIALOG_JS);

ui/webui/resources/cr_components/chromeos/smb_shares/add_smb_share_dialog.html

@@ -92,7 +92,7 @@
         </cr-input>
         <div id="authentication-method"
             hidden="[[!shouldShowAuthenticationUI_(isActiveDirectory_,
-                isKerberosEnabled_)]]">
+                isKerberosEnabled_, isGuest_)]]">
           <label id="authentication-label" class="cr-form-field-label">
             [[i18n('smbShareAuthenticationMethod')]]
           </label>

ui/webui/resources/cr_components/chromeos/smb_shares/add_smb_share_dialog.js

@@ -97,14 +97,31 @@ Polymer({
       },
     },
 
+    /** @private */
+    isGuest_: {
+      type: Boolean,
+      value() {
+        return loadTimeData.getBoolean('isGuest');
+      },
+    },
+
     /** @private */
     authenticationMethod_: {
       type: String,
       value() {
-        return loadTimeData.getBoolean('isActiveDirectoryUser') ||
-                loadTimeData.getBoolean('isKerberosEnabled') ?
-            SmbAuthMethod.KERBEROS :
-            SmbAuthMethod.CREDENTIALS;
+        // SSO not supported in guest mode. TODO(crbug/1186188): Enable SSO
+        // option for MGS on file share UI, after fixing authentication error.
+        if (loadTimeData.getBoolean('isGuest')) {
+          return SmbAuthMethod.CREDENTIALS;
+        }
+
+        // SSO only supported on ChromAD or Kerberos.
+        if (loadTimeData.getBoolean('isActiveDirectoryUser') ||
+            loadTimeData.getBoolean('isKerberosEnabled')) {
+          return SmbAuthMethod.KERBEROS;
+        }
+
+        return SmbAuthMethod.CREDENTIALS;
       },
       observer: 'onAuthenticationMethodChanged_',
     },
@@ -214,6 +231,13 @@ Polymer({
    * @private
    */
   shouldShowAuthenticationUI_() {
+    // SSO not supported in guest mode. TODO(crbug/1186188): Enable SSO option
+    // for MGS on file share UI, after fixing authentication error.
+    if (this.isGuest_) {
+      return false;
+    }
+
+    // SSO only supported on ChromAD or Kerberos.
     return this.isActiveDirectory_ || this.isKerberosEnabled_;
   },
 
@@ -246,7 +270,6 @@ Polymer({
             loadTimeData.getString('smbShareAddedInvalidUsernameMessage'));
         break;
 
-
       // Path Errors
       case SmbMountResult.NOT_FOUND:
         this.setPathError_(