Updates language model on iOS.

ios/chrome/browser/prefs/browser_prefs.mm

Index: ios/chrome/browser/prefs/browser_prefs.mm
diff --git a/ios/chrome/browser/prefs/browser_prefs.mm b/ios/chrome/browser/prefs/browser_prefs.mm
index 568823b883c782edfbb9b9957163d88e013d64ab..e0d5b3a02b14b4c53cf4bad580303895416d2356 100644
--- a/ios/chrome/browser/prefs/browser_prefs.mm
+++ b/ios/chrome/browser/prefs/browser_prefs.mm
@@ -33,6 +33,7 @@
 #include "components/ssl_config/ssl_config_service_manager.h"
 #include "components/strings/grit/components_locale_settings.h"
 #include "components/sync/base/sync_prefs.h"
+#include "components/translate/core/browser/language_model.h"
 #include "components/translate/core/browser/translate_pref_names.h"
 #include "components/translate/core/browser/translate_prefs.h"
 #include "components/update_client/update_client.h"
@@ -111,6 +112,7 @@ void RegisterBrowserStatePrefs(user_prefs::PrefRegistrySyncable* registry) {
   PrefProxyConfigTrackerImpl::RegisterProfilePrefs(registry);
   syncer::SyncPrefs::RegisterProfilePrefs(registry);
   TemplateURLPrepopulateData::RegisterProfilePrefs(registry);
+  translate::LanguageModel::RegisterProfilePrefs(registry);
   translate::TranslatePrefs::RegisterProfilePrefs(registry);
   variations::VariationsService::RegisterProfilePrefs(registry);
   ZeroSuggestProvider::RegisterProfilePrefs(registry);