If user profile doesn't contain language setting, default to his Google account settings.

chrome/browser/profiles/profile_impl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/profiles/profile_impl.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
+#include "base/debug/stack_trace.h"

[sail, 2013/09/09 22:02:17]

don't need?

 #include "base/debug/trace_event.h"
 #include "base/environment.h"
 #include "base/file_util.h"
 #include "base/files/file_path.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/path_service.h"
 #include "base/prefs/json_pref_store.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "base/version.h"
 #include "chrome/browser/autocomplete/autocomplete_classifier.h"
 #include "chrome/browser/background/background_contents_service_factory.h"
 #include "chrome/browser/background/background_mode_manager.h"
 #include "chrome/browser/bookmarks/bookmark_model.h"
 #include "chrome/browser/bookmarks/bookmark_model_factory.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chrome_notification_types.h"
+#include "chrome/browser/chromeos/login/language_switch_menu.h"

[sail, 2013/09/09 22:02:17]

don't need?

 #include "chrome/browser/content_settings/cookie_settings.h"
 #include "chrome/browser/content_settings/host_content_settings_map.h"
 #include "chrome/browser/download/chrome_download_manager_delegate.h"
 #include "chrome/browser/download/download_service.h"
 #include "chrome/browser/download/download_service_factory.h"
 #include "chrome/browser/extensions/extension_pref_store.h"
 #include "chrome/browser/extensions/extension_pref_value_map.h"
 #include "chrome/browser/extensions/extension_pref_value_map_factory.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/extension_special_storage_policy.h"
@@ skipping 989 matching lines @@
           if (locale_change_guard_ == NULL)
             locale_change_guard_.reset(new chromeos::LocaleChangeGuard(this));
           locale_change_guard_->PrepareChangingLocale(cur_locale, new_locale);
         }
       } else {
         std::string cur_locale = g_browser_process->GetApplicationLocale();
         std::string backup_locale =
             GetPrefs()->GetString(prefs::kApplicationLocaleBackup);
         // Profile synchronization takes time and is not completed at that
         // moment at first login.  So we initialize locale preference in steps:
         // (1) first save it to temporary backup;

[sail, 2013/09/09 22:02:17]

is this comment still valid?

[Alexander Alekseev, 2013/09/11 18:53:02]

I think so, as kApplicationLocale is not priority preference yet. (it's still
TODO to make it a priority).

         // (2) on next login we assume that synchronization is already completed
         //     and we may finalize initialization.
         GetPrefs()->SetString(prefs::kApplicationLocaleBackup, cur_locale);
-        if (!backup_locale.empty())
+        if (!new_locale.empty())
+          GetPrefs()->SetString(prefs::kApplicationLocale, new_locale);
+        else if (!backup_locale.empty())
           GetPrefs()->SetString(prefs::kApplicationLocale, backup_locale);
         do_update_pref = false;
       }
       break;
     }
     case APP_LOCALE_CHANGED_VIA_UNKNOWN:
     default: {
       NOTREACHED();
       break;
     }
@@ skipping 119 matching lines @@
 PrefProxyConfigTracker* ProfileImpl::CreateProxyConfigTracker() {
 #if defined(OS_CHROMEOS)
   if (chromeos::ProfileHelper::IsSigninProfile(this)) {
     return ProxyServiceFactory::CreatePrefProxyConfigTrackerOfLocalState(
         g_browser_process->local_state());
   }
 #endif  // defined(OS_CHROMEOS)
   return ProxyServiceFactory::CreatePrefProxyConfigTrackerOfProfile(
       GetPrefs(), g_browser_process->local_state());
 }