Updates language model on iOS.

ios/web_view/internal/translate/web_view_translate_client.mm

 // 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.
 
 #import "ios/web_view/internal/translate/web_view_translate_client.h"
 
 #include <vector>
 
 #include "base/logging.h"
 #import "base/mac/scoped_nsobject.h"
@@ skipping 26 matching lines @@
 WebViewTranslateClient::WebViewTranslateClient(web::WebState* web_state)
     : web::WebStateObserver(web_state),
       translate_manager_(base::MakeUnique<translate::TranslateManager>(
           this,
           WebViewTranslateRankerFactory::GetForBrowserState(
               WebViewBrowserState::FromBrowserState(
                   web_state->GetBrowserState())),
           prefs::kAcceptLanguages)),
       translate_driver_(web_state,
                         web_state->GetNavigationManager(),
-                        translate_manager_.get()) {}
+                        translate_manager_.get(),
+                        nil) {}

[jkrcal, 2017/06/02 08:35:09]

nit: /*language_model=*/nil

Why don't you feed the model from web_view? Is it simply consistent with other
behaviour of webview and user expectations thereof?

Could you also add a comment here explaining why "nil" is used?

[jkrcal, 2017/06/02 08:36:39]

Actually, I know nothing about code style for .mm files. Take my nit merely as a
comment that just "nil" is not very clear to me.

[ramyasharma, 2017/06/05 05:07:26]

Thanks Jan. The only reason I pass nil, is because
1. I don't know if this functionality needs to be part of webview
2. Even if it does, it was not straight forward, and needed some code
duplication in webview (i am not sure if I  depend on the factory class I
introduced here). So if required I will add this in the next CL after I discuss
it with the owners of webview. 

 
 WebViewTranslateClient::~WebViewTranslateClient() = default;
 
 // TranslateClient implementation:
 
 std::unique_ptr<infobars::InfoBar> WebViewTranslateClient::CreateInfoBar(
     std::unique_ptr<translate::TranslateInfoBarDelegate> delegate) const {
   NOTREACHED();
   return nullptr;
 }
@@ skipping 60 matching lines @@
 }
 
 void WebViewTranslateClient::WebStateDestroyed() {
   // Translation process can be interrupted.
   // Destroying the TranslateManager now guarantees that it never has to deal
   // with nullptr WebState.
   translate_manager_.reset();
 }
 
 }  // namespace ios_web_view