Implementation of translation event logging.

ios/chrome/browser/translate/chrome_ios_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.
 
 #include "ios/chrome/browser/translate/chrome_ios_translate_client.h"
 
 #include <utility>
 #include <vector>
 
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "components/infobars/core/infobar.h"
+#include "components/metrics/proto/translate_event.pb.h"
 #include "components/prefs/pref_service.h"
 #include "components/translate/core/browser/page_translated_details.h"
 #include "components/translate/core/browser/translate_accept_languages.h"
 #include "components/translate/core/browser/translate_infobar_delegate.h"
 #include "components/translate/core/browser/translate_manager.h"
 #include "components/translate/core/browser/translate_prefs.h"
 #include "components/translate/core/browser/translate_step.h"
 #include "ios/chrome/browser/browser_state/chrome_browser_state.h"
 #include "ios/chrome/browser/infobars/infobar.h"
 #include "ios/chrome/browser/infobars/infobar_controller.h"
@@ skipping 70 matching lines @@
           initWithDelegate:infobar.get()]);
       break;
     default:
       NOTREACHED();
   }
   infobar->SetController(controller);
   // TODO(crbug.com/703565): remove std::move() once Xcode 9.0+ is required.
   return std::move(infobar);
 }
 
+void ChromeIOSTranslateClient::RecordTranslateEvent(
+    const metrics::TranslateEventProto&) {
+  // TODO(renjieliu): Implementing gaia-keyed logging.

[Eugene But (OOO till 7-30), 2017/06/12 01:50:00]

In ios we normally use |TODO(crbug.com/<bug number>):| format, because people
leave but bugs stay.

[renjieliu1, 2017/06/13 00:04:59]

got it, thanks!

+}
+
 void ChromeIOSTranslateClient::ShowTranslateUI(
     translate::TranslateStep step,
     const std::string& source_language,
     const std::string& target_language,
     translate::TranslateErrors::Type error_type,
     bool triggered_from_menu) {
   DCHECK(web_state());
   if (error_type != translate::TranslateErrors::NONE)
     step = translate::TRANSLATE_STEP_TRANSLATE_ERROR;
 
@@ skipping 45 matching lines @@
     const GURL& report_url) {
   NOTREACHED();
 }
 
 void ChromeIOSTranslateClient::WebStateDestroyed() {
   // Translation process can be interrupted.
   // Destroying the TranslateManager now guarantees that it never has to deal
   // with nullptr WebState.
   translate_manager_.reset();
 }