ChromeOS NetworkScreenHandler should not call CheckAndResolveLocale on UI thread.

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

 // Copyright 2014 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.
 
 #ifndef CHROME_BROWSER_UI_WEBUI_CHROMEOS_LOGIN_L10N_UTIL_H_
 #define CHROME_BROWSER_UI_WEBUI_CHROMEOS_LOGIN_L10N_UTIL_H_
 
 #include <string>
 #include <vector>
 
 #include "base/callback.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/strings/string16.h"
+#include "chrome/browser/chromeos/base/locale_util.h"
 
 namespace base {
 class DictionaryValue;
 class ListValue;
 }
 
 namespace chromeos {
 
+typedef base::Callback<void(scoped_ptr<base::ListValue> /* new_language_list */,
+                            std::string /* new_language_list_locale */,
+                            std::string /* new_selected_language */)>
+    UILanguageListResolvedCallback;
+
 // GetUILanguageList() returns a concatenated list of the most relevant
 // languages followed by all others. An entry with its "code" attribute set to
 // this value is inserted in between.
 extern const char kMostRelevantLanguagesDivider[];
 
 // Utility methods for retrieving lists of supported locales and input methods /
 // keyboard layouts during OOBE and on the login screen.
 
+// Helper function for GetUILanguageList.
+// Requires |language_display_name| after
+// base::i18n::UnadjustStringForLocaleDirection.
+const std::string GetLanguageDirectionality(
+    const base::string16& language_display_name);
+
 // Return a list of languages in which the UI can be shown. Each list entry is a
 // dictionary that contains data such as the language's locale code and a
 // display name. The list will consist of the |most_relevant_language_codes|,
 // followed by a divider and all other supported languages after that. If
 // |most_relevant_language_codes| is NULL, the most relevant languages are read
 // from initial_locale in VPD. If |selected| matches the locale code of any
 // entry in the resulting list, that entry will be marked as selected.
 scoped_ptr<base::ListValue> GetUILanguageList(
     const std::vector<std::string>* most_relevant_language_codes,
     const std::string& selected);
 
+// Must be called on UI thread. Runs GetUILanguageList(), on Blocking Pool,
+// and calls |callback| on UI thread with result.
+void ResolveUILanguageList(
+    scoped_ptr<locale_util::LanguageSwitchResult> language_switch_result,

[dzhioev (left Google), 2014/10/02 14:12:10]

Please, describe in a comment what's happening when language_switch_result is
null.

[Alexander Alekseev, 2014/10/02 19:05:03]

Done.

+    UILanguageListResolvedCallback callback);
+
+// Returns a minimal list of UI languages, which consists of active language
+// only. It is used as a placeholder until ResolveUILanguageList() finishes
+// on BlockingPool.
+scoped_ptr<base::ListValue> GetMinimalUILanguageList();
+
 // Returns the most first entry of |most_relevant_language_codes| that is
 // actually available (present in |available_locales|). If none of the entries
 // are present in |available_locales|, returns the |fallback_locale|.
 std::string FindMostRelevantLocale(
     const std::vector<std::string>& most_relevant_language_codes,
     const base::ListValue& available_locales,
     const std::string& fallback_locale);
 
 // Return a list of supported accept languages. The listed languages can be used
 // in the Accept-Language header. The return value will look like:
@@ skipping 27 matching lines @@
     const GetKeyboardLayoutsForLocaleCallback& callback,
     const std::string& locale);
 
 // Returns the current keyboard layout, expressed as a dictionary that contains
 // data such as an ID and a display name.
 scoped_ptr<base::DictionaryValue> GetCurrentKeyboardLayout();
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_UI_WEBUI_CHROMEOS_LOGIN_L10N_UTIL_H_