[Demo Mode] Keep the locale variant selected during OOBE.

In OOBE, during enrollment into Demo Mode, the user selects a locale
variant. That selection is stored both in the locale state and the
profile preferences. However, the profile is discarded and a new profile is
always used when a Demo Mode session starts. For this reason, the locale
selected by the user is lost and only the fallback browser locale is
kept. This means that "fr-CA" becomes "fr" for Demo Mode.

This change allows Demo Mode to check for the local state locale after
a new session has started, which is set as the application locale of the
profile for the remained of the session.

Bug: b:158695273
Change-Id: I6c7d3f0508ee1a6bd4078309bb9e6110e8968c9b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2251138
Commit-Queue: Claudio M <claudiomagni@chromium.org>
Reviewed-by: Roman Sorokin [CET] <rsorokin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#781088}

chrome/browser/chromeos/login/session/user_session_manager.cc

@@ -761,6 +761,16 @@ bool UserSessionManager::RespectLocalePreference(
       prefs->GetString(prefs::kApplicationLocaleBackup);
 
   pref_locale = pref_app_locale;
+
+  // In Demo Mode, each sessions uses a new empty User Profile, so we need to
+  // rely on the local state set in the browser process.
+  if (chromeos::DemoSession::IsDeviceInDemoMode() && pref_app_locale.empty()) {
+    const std::string local_state_locale =
+        g_browser_process->local_state()->GetString(
+            language::prefs::kApplicationLocale);
+    pref_locale = local_state_locale;
+  }
+
   if (pref_locale.empty())
     pref_locale = pref_bkup_locale;
 

chrome/browser/chromeos/login/session/user_session_manager_test.cc

@@ -5,10 +5,20 @@
 #include "chrome/browser/chromeos/login/session/user_session_manager.h"
 
 #include "base/macros.h"
+#include "base/strings/utf_string_conversions.h"
+#include "chrome/browser/chromeos/login/demo_mode/demo_session.h"
+#include "chrome/browser/chromeos/login/users/fake_chrome_user_manager.h"
+#include "chrome/browser/chromeos/profiles/profile_helper.h"
+#include "chrome/browser/prefs/browser_prefs.h"
+#include "chrome/test/base/testing_browser_process.h"
+#include "chrome/test/base/testing_profile.h"
+#include "chrome/test/base/testing_profile_manager.h"
 #include "chromeos/dbus/session_manager/fake_session_manager_client.h"
 #include "chromeos/dbus/session_manager/session_manager_client.h"
 #include "chromeos/login/auth/key.h"
 #include "chromeos/login/auth/user_context.h"
+#include "components/language/core/browser/pref_names.h"
+#include "components/sync_preferences/testing_pref_service_syncable.h"
 #include "components/user_manager/fake_user_manager.h"
 #include "components/user_manager/scoped_user_manager.h"
 #include "content/public/browser/network_service_instance.h"
@@ -34,7 +44,9 @@ class TestUserSessionManager : public UserSessionManager {
 
 class UserSessionManagerTest : public testing::Test {
  public:
-  UserSessionManagerTest() {
+  UserSessionManagerTest()
+      : profile_manager_(std::make_unique<TestingProfileManager>(
+            TestingBrowserProcess::GetGlobal())) {
     static_assert(
         static_cast<int>(
             UserSessionManager::PasswordConsumingService::kCount) == 2,
@@ -44,7 +56,10 @@ class UserSessionManagerTest : public testing::Test {
     user_session_manager_ = std::make_unique<TestUserSessionManager>();
   }
 
+  void SetUp() override { ASSERT_TRUE(profile_manager_->SetUp()); }
+
   ~UserSessionManagerTest() override {
+    profile_manager_->DeleteAllTestingProfiles();
     user_session_manager_.reset();
     SessionManagerClient::Shutdown();
   }
@@ -66,6 +81,28 @@ class UserSessionManagerTest : public testing::Test {
     return user_session_manager_->user_context().GetPasswordKey()->GetSecret();
   }
 
+  // Creates a dummy user with a testing profile and logs in.
+  TestingProfile* LoginTestUser() {
+    const AccountId account_id(
+        AccountId::FromUserEmailGaiaId("demo@test.com", "demo_user"));
+    FakeChromeUserManager* user_manager =
+        static_cast<FakeChromeUserManager*>(user_manager::UserManager::Get());
+    test_user_ = user_manager->AddPublicAccountUser(account_id);
+
+    auto prefs =
+        std::make_unique<sync_preferences::TestingPrefServiceSyncable>();
+    RegisterUserProfilePrefs(prefs->registry());
+    TestingProfile* profile = profile_manager_->CreateTestingProfile(
+        "test-profile", std::move(prefs), base::ASCIIToUTF16("Test profile"),
+        1 /* avatar_id */, std::string() /* supervised_user_id */,
+        TestingProfile::TestingFactories());
+    chromeos::ProfileHelper::Get()->SetUserToProfileMappingForTesting(
+        test_user_, profile);
+
+    user_manager->LoginUser(account_id);
+    return profile;
+  }
+
   std::unique_ptr<TestUserSessionManager> user_session_manager_;
 
   // Allows UserSessionManager to request the NetworkConnectionTracker in its
@@ -75,6 +112,9 @@ class UserSessionManagerTest : public testing::Test {
   user_manager::ScopedUserManager scoped_user_manager_{
       std::make_unique<user_manager::FakeUserManager>()};
 
+  std::unique_ptr<TestingProfileManager> profile_manager_;
+  user_manager::User* test_user_;
+
  private:
   DISALLOW_COPY_AND_ASSIGN(UserSessionManagerTest);
 };
@@ -137,4 +177,77 @@ TEST_F(UserSessionManagerTest, PasswordConsumerService_NoSave_Save) {
   EXPECT_TRUE(GetUserSessionManagerLoginPassword().empty());
 }
 
+TEST_F(UserSessionManagerTest, RespectLocale_WithProfileLocale) {
+  TestingProfile* profile = LoginTestUser();
+
+  profile->GetPrefs()->SetString(language::prefs::kApplicationLocale, "fr-CA");
+  g_browser_process->SetApplicationLocale("fr");
+
+  // Local state locale should be ignored.
+  TestingBrowserProcess::GetGlobal()->local_state()->SetString(
+      language::prefs::kApplicationLocale, "es");
+
+  user_session_manager_->RespectLocalePreference(profile, test_user_,
+                                                 base::NullCallback());
+
+  EXPECT_TRUE(profile->requested_locale().has_value());
+  EXPECT_EQ("fr-CA", profile->requested_locale().value());
+}
+
+TEST_F(UserSessionManagerTest, RespectLocale_WithoutProfileLocale) {
+  TestingProfile* profile = LoginTestUser();
+
+  g_browser_process->SetApplicationLocale("fr");
+
+  // Local state locale should be ignored.
+  TestingBrowserProcess::GetGlobal()->local_state()->SetString(
+      language::prefs::kApplicationLocale, "es");
+
+  user_session_manager_->RespectLocalePreference(profile, test_user_,
+                                                 base::NullCallback());
+
+  EXPECT_TRUE(profile->requested_locale().has_value());
+  EXPECT_EQ("fr", profile->requested_locale().value());
+}
+
+TEST_F(UserSessionManagerTest, RespectLocale_Demo_WithProfileLocale) {
+  TestingProfile* profile = LoginTestUser();
+  // Enable Demo Mode.
+  chromeos::DemoSession::SetDemoConfigForTesting(
+      chromeos::DemoSession::DemoModeConfig::kOnline);
+
+  profile->GetPrefs()->SetString(language::prefs::kApplicationLocale, "fr-CA");
+  g_browser_process->SetApplicationLocale("fr");
+
+  // Local state locale should be ignored.
+  TestingBrowserProcess::GetGlobal()->local_state()->SetString(
+      language::prefs::kApplicationLocale, "es");
+
+  user_session_manager_->RespectLocalePreference(profile, test_user_,
+                                                 base::NullCallback());
+
+  EXPECT_TRUE(profile->requested_locale().has_value());
+  EXPECT_EQ("fr-CA", profile->requested_locale().value());
+}
+
+TEST_F(UserSessionManagerTest, RespectLocale_Demo_WithoutProfileLocale) {
+  TestingProfile* profile = LoginTestUser();
+  // Enable Demo Mode.
+  chromeos::DemoSession::SetDemoConfigForTesting(
+      chromeos::DemoSession::DemoModeConfig::kOnline);
+
+  g_browser_process->SetApplicationLocale("fr");
+
+  // Because it's Demo Mode and the profile pref local is empty, local state
+  // locale should not be ignored.
+  TestingBrowserProcess::GetGlobal()->local_state()->SetString(
+      language::prefs::kApplicationLocale, "fr-CA");
+
+  user_session_manager_->RespectLocalePreference(profile, test_user_,
+                                                 base::NullCallback());
+
+  EXPECT_TRUE(profile->requested_locale().has_value());
+  EXPECT_EQ("fr-CA", profile->requested_locale().value());
+}
+
 }  // namespace chromeos