Disable Guest sign-in button for child devices for WebUI.

Bug: 823534

Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: I062d1ef97feb3778622e48dfc75d353e0a4dd1e9
Reviewed-on: https://chromium-review.googlesource.com/1067682
Commit-Queue: Xiyuan Xia <xiyuan@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#561593}

chrome/browser/chromeos/login/users/chrome_user_manager_util.cc

@@ -12,6 +12,7 @@
 #include "chrome/browser/chromeos/settings/device_settings_provider.h"
 #include "chromeos/settings/cros_settings_names.h"
 #include "components/prefs/pref_value_map.h"
+#include "components/user_manager/user_manager.h"
 #include "components/user_manager/user_names.h"
 #include "components/user_manager/user_type.h"
 
@@ -110,6 +111,18 @@ bool AreSupervisedUsersAllowed(const CrosSettings* cros_settings) {
 }
 
 bool IsGuestSessionAllowed(const CrosSettings* cros_settings) {
+  const AccountId& owner_account_id =
+      user_manager::UserManager::Get()->GetOwnerAccountId();
+  if (owner_account_id.is_valid() &&
+      user_manager::UserManager::Get()->FindUser(owner_account_id)->GetType() ==
+          user_manager::UserType::USER_TYPE_CHILD) {
+    return false;
+  }
+
+  // In tests CrosSettings might not be initialized.
+  if (!cros_settings)
+    return false;
+
   bool is_guest_allowed = false;
   cros_settings->GetBoolean(kAccountsPrefAllowGuest, &is_guest_allowed);
   return is_guest_allowed;

chrome/browser/ui/webui/chromeos/login/gaia_screen_handler.cc

@@ -31,6 +31,7 @@
 #include "chrome/browser/chromeos/login/ui/login_display_host_webui.h"
 #include "chrome/browser/chromeos/login/ui/user_adding_screen.h"
 #include "chrome/browser/chromeos/login/users/chrome_user_manager.h"
+#include "chrome/browser/chromeos/login/users/chrome_user_manager_util.h"
 #include "chrome/browser/chromeos/net/network_portal_detector_impl.h"
 #include "chrome/browser/chromeos/policy/browser_policy_connector_chromeos.h"
 #include "chrome/browser/chromeos/policy/temp_certs_cache_nss.h"
@@ -173,9 +174,9 @@ void UpdateAuthParams(base::DictionaryValue* params,
   CrosSettings* cros_settings = CrosSettings::Get();
   bool allow_new_user = true;
   cros_settings->GetBoolean(kAccountsPrefAllowNewUser, &allow_new_user);
-  bool allow_guest = true;
-  cros_settings->GetBoolean(kAccountsPrefAllowGuest, &allow_guest);
-  params->SetBoolean("guestSignin", allow_guest);
+  params->SetBoolean(
+      "guestSignin",
+      chrome_user_manager_util::IsGuestSessionAllowed(cros_settings));
 
   // nosignup flow if new users are not allowed.
   if (!allow_new_user || is_restrictive_proxy)

chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc

@@ -57,6 +57,7 @@
 #include "chrome/browser/chromeos/login/ui/login_display_host_webui.h"
 #include "chrome/browser/chromeos/login/ui/login_display_webui.h"
 #include "chrome/browser/chromeos/login/ui/login_feedback.h"
+#include "chrome/browser/chromeos/login/users/chrome_user_manager_util.h"
 #include "chrome/browser/chromeos/login/users/multi_profile_user_controller.h"
 #include "chrome/browser/chromeos/login/wizard_controller.h"
 #include "chrome/browser/chromeos/policy/browser_policy_connector_chromeos.h"
@@ -862,7 +863,7 @@ void SigninScreenHandler::SetupAndShowOfflineMessage(
   }
 
   const bool guest_signin_allowed =
-      IsGuestSigninAllowed() &&
+      chrome_user_manager_util::IsGuestSessionAllowed(CrosSettings::Get()) &&
       IsSigninScreenError(error_screen_->GetErrorState());
   error_screen_->AllowGuestSignin(guest_signin_allowed);
 
@@ -1711,15 +1712,6 @@ bool SigninScreenHandler::IsSigninScreenHiddenByError() const {
          (IsSigninScreen(error_screen_->GetParentScreen()));
 }
 
-bool SigninScreenHandler::IsGuestSigninAllowed() const {
-  CrosSettings* cros_settings = CrosSettings::Get();
-  if (!cros_settings)
-    return false;
-  bool allow_guest;
-  cros_settings->GetBoolean(kAccountsPrefAllowGuest, &allow_guest);
-  return allow_guest;
-}
-
 net::Error SigninScreenHandler::FrameError() const {
   return gaia_screen_handler_->frame_error();
 }

chrome/browser/ui/webui/chromeos/login/signin_screen_handler.h

@@ -461,9 +461,6 @@ class SigninScreenHandler
   // screen.
   bool IsSigninScreenHiddenByError() const;
 
-  // Returns true if guest signin is allowed.
-  bool IsGuestSigninAllowed() const;
-
   bool ShouldLoadGaia() const;
 
   net::Error FrameError() const;