Reland "Welcome screen: Fix language list initialization"

This is a reland of 71c00bee

Original change's description:
> Welcome screen: Fix language list initialization
> 
> Change ResolveLanguageListInThreadPool so that it uses AppLocale instead
> of default locale if exists.
> 
> Bug: 955397
> Change-Id: I6947dd89e297adea3fd019e38d083e45419ea282
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1704098
> Reviewed-by: Alexander Alekseev <alemate@chromium.org>
> Reviewed-by: Denis Kuznetsov <antrim@chromium.org>
> Reviewed-by: Roman Sorokin [CET] <rsorokin@chromium.org>
> Commit-Queue: Roman Aleksandrov <raleksandrov@google.com>
> Cr-Commit-Position: refs/heads/master@{#706436}

Bug: 955397
Change-Id: I9b6bc855f0a87eadab42af14d5e3d797f77d6a57
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1865227
Commit-Queue: Roman Aleksandrov <raleksandrov@google.com>
Reviewed-by: Roman Sorokin [CET] <rsorokin@chromium.org>
Reviewed-by: Alexander Alekseev <alemate@chromium.org>
Cr-Commit-Position: refs/heads/master@{#707295}

chrome/browser/chromeos/customization/customization_document.cc

@@ -39,6 +39,7 @@
 #include "chrome/browser/ui/app_list/app_list_syncable_service_factory.h"
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/pref_names.h"
+#include "chromeos/constants/chromeos_paths.h"
 #include "chromeos/system/statistics_provider.h"
 #include "components/pref_registry/pref_registry_syncable.h"
 #include "components/prefs/pref_registry_simple.h"
@@ -73,10 +74,6 @@ const char kIdAttr[] = "id";
 
 const char kAcceptedManifestVersion[] = "1.0";
 
-// Path to OEM partner startup customization manifest.
-const char kStartupCustomizationManifestPath[] =
-    "/opt/oem/etc/startup_manifest.json";
-
 // This is subdirectory relative to PathService(DIR_CHROMEOS_CUSTOM_WALLPAPERS),
 // where downloaded (and resized) wallpaper is stored.
 const char kCustomizationDefaultWallpaperDir[] = "customization";
@@ -287,7 +284,10 @@ StartupCustomizationDocument::StartupCustomizationDocument()
     // Loading manifest causes us to do blocking IO on UI thread.
     // Temporarily allow it until we fix http://crosbug.com/11103
     base::ThreadRestrictions::ScopedAllowIO allow_io;
-    LoadManifestFromFile(base::FilePath(kStartupCustomizationManifestPath));
+    base::FilePath startup_customization_manifest;
+    base::PathService::Get(chromeos::FILE_STARTUP_CUSTOMIZATION_MANIFEST,
+                           &startup_customization_manifest);
+    LoadManifestFromFile(startup_customization_manifest);
   }
   Init(system::StatisticsProvider::GetInstance());
 }

chrome/browser/chromeos/login/screens/welcome_screen_browsertest.cc

@@ -2,6 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include <memory>
+
+#include "base/test/scoped_path_override.h"
+#include "base/test/task_environment.h"
 #include "build/build_config.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chromeos/accessibility/accessibility_manager.h"
@@ -11,11 +15,17 @@
 #include "chrome/browser/chromeos/login/test/js_checker.h"
 #include "chrome/browser/chromeos/login/test/oobe_base_test.h"
 #include "chrome/browser/chromeos/login/test/oobe_screen_waiter.h"
+#include "chrome/browser/chromeos/login/test/test_predicate_waiter.h"
 #include "chrome/browser/chromeos/login/ui/login_display_host.h"
 #include "chrome/browser/chromeos/login/wizard_controller.h"
 #include "chrome/browser/ui/webui/chromeos/login/oobe_ui.h"
 #include "chrome/browser/ui/webui/chromeos/login/welcome_screen_handler.h"
+#include "chromeos/constants/chromeos_paths.h"
 #include "chromeos/dbus/constants/dbus_switches.h"
+#include "components/language/core/browser/pref_names.h"
+#include "components/prefs/pref_service.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
 #include "ui/accessibility/accessibility_switches.h"
 #include "ui/base/ime/chromeos/extension_ime_util.h"
 
@@ -23,6 +33,14 @@ namespace chromeos {
 
 namespace {
 
+const char kStartupManifest[] =
+    R"({
+      "version": "1.0",
+      "initial_locale" : "en-US",
+      "initial_timezone" : "US/Pacific",
+      "keyboard_layout" : "xkb:us::eng",
+    })";
+
 chromeos::OobeUI* GetOobeUI() {
   auto* host = chromeos::LoginDisplayHost::default_host();
   return host ? host->GetOobeUI() : nullptr;
@@ -45,6 +63,27 @@ void ToggleAccessibilityFeature(const std::string& feature_name,
   js.CreateWaiter(feature_toggle)->Wait();
 }
 
+class LanguageReloadObserver : public WelcomeScreen::Observer {
+ public:
+  explicit LanguageReloadObserver(WelcomeScreen* welcome_screen)
+      : welcome_screen_(welcome_screen) {
+    welcome_screen_->AddObserver(this);
+  }
+
+  // WelcomeScreen::Observer:
+  void OnLanguageListReloaded() override { run_loop_.Quit(); }
+
+  void Wait() { run_loop_.Run(); }
+
+  ~LanguageReloadObserver() override { welcome_screen_->RemoveObserver(this); }
+
+ private:
+  WelcomeScreen* const welcome_screen_;
+  base::RunLoop run_loop_;
+
+  DISALLOW_COPY_AND_ASSIGN(LanguageReloadObserver);
+};
+
 }  // namespace
 
 class WelcomeScreenBrowserTest : public InProcessBrowserTest {
@@ -55,8 +94,18 @@ class WelcomeScreenBrowserTest : public InProcessBrowserTest {
   // InProcessBrowserTest:
 
   void SetUpOnMainThread() override {
-    ShowLoginWizard(OobeScreen::SCREEN_TEST_NO_WINDOW);
+    ASSERT_TRUE(data_dir_.CreateUniqueTempDir());
+    base::FilePath startup_manifest =
+        data_dir_.GetPath().AppendASCII("startup_manifest.json");
+    base::WriteFile(startup_manifest, kStartupManifest,
+                    strlen(kStartupManifest));
+    path_override_ = std::make_unique<base::ScopedPathOverride>(
+        chromeos::FILE_STARTUP_CUSTOMIZATION_MANIFEST, startup_manifest);
 
+    ShowLoginWizard(OobeScreen::SCREEN_TEST_NO_WINDOW);
+    test::TestPredicateWaiter(base::BindRepeating([]() {
+      return WizardController::default_controller() != nullptr;
+    })).Wait();
     WizardController::default_controller()
         ->screen_manager()
         ->DeleteScreenForTesting(WelcomeView::kScreenId);
@@ -65,12 +114,18 @@ class WelcomeScreenBrowserTest : public InProcessBrowserTest {
         base::BindRepeating(&WelcomeScreenBrowserTest::OnWelcomeScreenExit,
                             base::Unretained(this)));
     welcome_screen_ = welcome_screen.get();
+    observer_ = std::make_unique<LanguageReloadObserver>(welcome_screen_);
     WizardController::default_controller()
         ->screen_manager()
         ->SetScreenForTesting(std::move(welcome_screen));
     InProcessBrowserTest::SetUpOnMainThread();
   }
 
+  void TearDownOnMainThread() override {
+    observer_.reset();
+    InProcessBrowserTest::TearDownOnMainThread();
+  }
+
   void WaitForScreenExit() {
     if (screen_exit_)
       return;
@@ -87,8 +142,11 @@ class WelcomeScreenBrowserTest : public InProcessBrowserTest {
   }
 
   WelcomeScreen* welcome_screen_ = nullptr;
+  std::unique_ptr<LanguageReloadObserver> observer_;
 
  private:
+  std::unique_ptr<base::ScopedPathOverride> path_override_;
+  base::ScopedTempDir data_dir_;
   bool screen_exit_ = false;
 
   base::OnceClosure screen_exit_callback_;
@@ -322,6 +380,29 @@ IN_PROC_BROWSER_TEST_F(WelcomeScreenBrowserTest,
   test::OobeJS().ExpectHiddenPath({"connect", "dockedMagnifierOobeOption"});
 }
 
+IN_PROC_BROWSER_TEST_F(WelcomeScreenBrowserTest, PRE_SelectedLanguage) {
+  EXPECT_EQ(
+      StartupCustomizationDocument::GetInstance()->initial_locale_default(),
+      "en-US");
+  welcome_screen_->Show();
+  OobeScreenWaiter(WelcomeView::kScreenId).Wait();
+  const std::string locale = "ru";
+  welcome_screen_->SetApplicationLocale(locale);
+  test::OobeJS().TapOnPath({"connect", "welcomeScreen", "welcomeNextButton"});
+  WaitForScreenExit();
+  EXPECT_EQ(g_browser_process->local_state()->GetString(
+                language::prefs::kApplicationLocale),
+            locale);
+}
+
+IN_PROC_BROWSER_TEST_F(WelcomeScreenBrowserTest, SelectedLanguage) {
+  observer_->Wait();
+  const std::string locale = "ru";
+  EXPECT_EQ(g_browser_process->local_state()->GetString(
+                language::prefs::kApplicationLocale),
+            locale);
+}
+
 IN_PROC_BROWSER_TEST_F(WelcomeScreenWithExperimentalAccessibilityFeaturesTest,
                        A11yDockedMagnifierEnabled) {
   welcome_screen_->Show();

chrome/browser/ui/webui/chromeos/login/l10n_util.cc

@@ -354,8 +354,12 @@ void ResolveLanguageListInThreadPool(
 
   std::string selected_language;
   if (!language_switch_result) {
-    selected_language =
-        StartupCustomizationDocument::GetInstance()->initial_locale_default();
+    if (!g_browser_process->GetApplicationLocale().empty()) {
+      selected_language = g_browser_process->GetApplicationLocale();
+    } else {
+      selected_language =
+          StartupCustomizationDocument::GetInstance()->initial_locale_default();
+    }
   } else {
     if (language_switch_result->success) {
       if (language_switch_result->requested_locale ==

chromeos/constants/chromeos_paths.cc

@@ -34,6 +34,9 @@ const base::FilePath::CharType kUptimeFileName[] =
 const base::FilePath::CharType kUpdateRebootNeededUptimeFile[] =
     FILE_PATH_LITERAL("/run/chrome/update_reboot_needed_uptime");
 
+const base::FilePath::CharType kStartupCustomizationManifestFile[] =
+    FILE_PATH_LITERAL("/opt/oem/etc/startup_manifest.json");
+
 const base::FilePath::CharType kDeviceLocalAccountExtensionDir[] =
     FILE_PATH_LITERAL("/var/cache/device_local_account_extensions");
 
@@ -75,6 +78,9 @@ bool PathProvider(int key, base::FilePath* result) {
     case FILE_UPDATE_REBOOT_NEEDED_UPTIME:
       *result = base::FilePath(kUpdateRebootNeededUptimeFile);
       break;
+    case FILE_STARTUP_CUSTOMIZATION_MANIFEST:
+      *result = base::FilePath(kStartupCustomizationManifestFile);
+      break;
     case DIR_DEVICE_LOCAL_ACCOUNT_EXTENSIONS:
       *result = base::FilePath(kDeviceLocalAccountExtensionDir);
       break;

chromeos/constants/chromeos_paths.h

@@ -29,6 +29,8 @@ enum {
                                      // store the uptime at which an update
                                      // became necessary. The file should be
                                      // cleared on boot.
+  FILE_STARTUP_CUSTOMIZATION_MANIFEST,     // Path to OEM partner startup
+                                           // customization manifest.
   DIR_DEVICE_LOCAL_ACCOUNT_EXTENSIONS,     // Directory under which a cache of
                                            // force-installed extensions is
                                            // maintained for each device-local