Implementation of translation event logging.

ios/chrome/browser/translate/chrome_ios_translate_client.mm

Index: ios/chrome/browser/translate/chrome_ios_translate_client.mm
diff --git a/ios/chrome/browser/translate/chrome_ios_translate_client.mm b/ios/chrome/browser/translate/chrome_ios_translate_client.mm
index b474a2808e9824d21771cc77688f152b2f04b04e..adc2e5192242eb370f3a24ac3cfbb6bfdbf83e93 100644
--- a/ios/chrome/browser/translate/chrome_ios_translate_client.mm
+++ b/ios/chrome/browser/translate/chrome_ios_translate_client.mm
@@ -10,6 +10,7 @@
 #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"
@@ -100,6 +101,11 @@ std::unique_ptr<infobars::InfoBar> ChromeIOSTranslateClient::CreateInfoBar(
   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,