Do not use local override for language settings: always sync.

chrome/browser/profiles/profile_impl.cc

 // Copyright (c) 2011 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/command_line.h"
 #include "base/environment.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
@@ skipping 1348 matching lines @@
     }
   }
   */
   return instant_promo_counter_.get();
 #else
   return NULL;
 #endif
 }
 
 #if defined(OS_CHROMEOS)
-void ProfileImpl::ChangeApplicationLocale(
-    const std::string& locale, bool keep_local) {
+void ProfileImpl::ChangeApplicationLocale(const std::string& locale) {
   if (locale.empty()) {
     NOTREACHED();
     return;
   }
-  if (keep_local) {
-    GetPrefs()->SetString(prefs::kApplicationLocaleOverride, locale);
-  } else {
-    GetPrefs()->SetString(prefs::kApplicationLocale, locale);
-    GetPrefs()->ClearPref(prefs::kApplicationLocaleOverride);
-  }
+  GetPrefs()->SetString(prefs::kApplicationLocale, locale);
   GetPrefs()->SetString(prefs::kApplicationLocaleBackup, locale);

[Nikita (slow), 2011/01/25 14:35:31]

Why kApplicationLocaleBackup / Accepted prefs state is different after local
change if compared with local change guard operations on these prefs.

[Denis Lagno, 2011/01/25 15:46:43]

Backup must not be cleared.  Backup should be kept as a reference.  In case
kApplicationLocale would change due to sync from other device then this Backup
value will allow us to show notification.
Added comment on that.

OTOH kApplicationLocaleAccepted can be cleared to make it clear that we allow
notifications again; or it can be just left equal to old value, I don't think it
matters.

   GetPrefs()->ClearPref(prefs::kApplicationLocaleAccepted);
   // We maintain kApplicationLocale property in both a global storage
   // and user's profile.  Global property determines locale of login screen,
   // while user's profile determines his personal locale preference.
   g_browser_process->local_state()->SetString(
       prefs::kApplicationLocale, locale);
 
   GetPrefs()->SavePersistentPrefs();
   g_browser_process->local_state()->SavePersistentPrefs();
 }
@@ skipping 22 matching lines @@
 }
 
 PrerenderManager* ProfileImpl::GetPrerenderManager() {
   CommandLine* cl = CommandLine::ForCurrentProcess();
   if (!cl->HasSwitch(switches::kEnablePagePrerender))
     return NULL;
   if (!prerender_manager_)
     prerender_manager_ = new PrerenderManager(this);
   return prerender_manager_;
 }