Updates language model on iOS.

ios/chrome/browser/browsing_data/ios_chrome_browsing_data_remover.mm

 // Copyright 2015 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 "ios/chrome/browser/browsing_data/ios_chrome_browsing_data_remover.h"
 
 #include <map>
 #include <set>
 #include <string>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/callback.h"
 #include "base/logging.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/metrics/user_metrics.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "components/autofill/core/browser/personal_data_manager.h"
 #include "components/autofill/core/browser/webdata/autofill_webdata_service.h"
 #include "components/history/core/browser/history_service.h"
 #include "components/keyed_service/core/service_access_type.h"
 #include "components/omnibox/browser/omnibox_pref_names.h"
 #include "components/password_manager/core/browser/password_store.h"
 #include "components/prefs/pref_service.h"
 #include "components/search_engines/template_url_service.h"
 #include "components/sessions/core/tab_restore_service.h"
+#include "components/translate/core/browser/language_model.h"
 #include "ios/chrome/browser/application_context.h"
 #include "ios/chrome/browser/autofill/personal_data_manager_factory.h"
 #include "ios/chrome/browser/browser_state/chrome_browser_state.h"
 #include "ios/chrome/browser/history/history_service_factory.h"
 #include "ios/chrome/browser/history/web_history_service_factory.h"
 #include "ios/chrome/browser/ios_chrome_io_thread.h"
 #include "ios/chrome/browser/passwords/ios_chrome_password_store_factory.h"
 #include "ios/chrome/browser/search_engines/template_url_service_factory.h"
 #include "ios/chrome/browser/sessions/ios_chrome_tab_restore_service_factory.h"
+#include "ios/chrome/browser/translate/language_model_factory.h"
 #include "ios/chrome/browser/web_data_service_factory.h"
 #include "ios/net/http_cache_helper.h"
 #include "ios/public/provider/chrome/browser/chrome_browser_provider.h"
 #include "ios/web/public/web_thread.h"
 #include "net/base/net_errors.h"
 #include "net/cookies/cookie_store.h"
 #include "net/http/transport_security_state.h"
 #include "net/ssl/channel_id_service.h"
 #include "net/ssl/channel_id_store.h"
 #include "net/url_request/url_request_context.h"
@@ skipping 297 matching lines @@
   CookieOrCacheDeletionChoice choice = NEITHER_COOKIES_NOR_CACHE;
   if (remove_mask & REMOVE_COOKIES) {
     choice = remove_mask & REMOVE_CACHE ? BOTH_COOKIES_AND_CACHE : ONLY_COOKIES;
   } else if (remove_mask & REMOVE_CACHE) {
     choice = ONLY_CACHE;
   }
 
   UMA_HISTOGRAM_ENUMERATION(
       "History.ClearBrowsingData.UserDeletedCookieOrCache", choice,
       MAX_CHOICE_VALUE);
+
+  // Remove language model history.

[martis, 2017/06/01 06:49:21]

I believe the language model should only be cleared if the user requests a
history clear (as opposed to e.g. a cookie clear); at least, this is the
behavior for non-iOS Chrome. 

This logic should be moved to line 249.

[ramyasharma, 2017/06/02 07:20:24]

Thanks, good catch. 

+  translate::LanguageModel* language_model =
+      translate::LanguageModelFactory::GetForBrowserState(browser_state_);
+  if (language_model) {
+    language_model->ClearHistory(delete_begin_, delete_end_);
+  }
 }
 
 void IOSChromeBrowsingDataRemover::AddObserver(Observer* observer) {
   observer_list_.AddObserver(observer);
 }
 
 void IOSChromeBrowsingDataRemover::RemoveObserver(Observer* observer) {
   observer_list_.RemoveObserver(observer);
 }
 
@@ skipping 144 matching lines @@
   waiting_for_clear_autofill_origin_urls_ = false;
   NotifyAndDeleteIfDone();
 }
 
 // static
 IOSChromeBrowsingDataRemover::CallbackSubscription
 IOSChromeBrowsingDataRemover::RegisterOnBrowsingDataRemovedCallback(
     const IOSChromeBrowsingDataRemover::Callback& callback) {
   return GetOnBrowsingDataRemovedCallbacks()->Add(callback);
 }