Send TranslateEventProtos to UMA.

chrome/browser/translate/chrome_translate_client.cc

Index: chrome/browser/translate/chrome_translate_client.cc
diff --git a/chrome/browser/translate/chrome_translate_client.cc b/chrome/browser/translate/chrome_translate_client.cc
index 06ce2bbbcd236307ca099d12faf0e7064c05534a..d35f12989de59b81f61e7032025acfde2f7a3b57 100644
--- a/chrome/browser/translate/chrome_translate_client.cc
+++ b/chrome/browser/translate/chrome_translate_client.cc
@@ -35,6 +35,7 @@
 #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_ranker.h"
 #include "components/translate/core/common/language_detection_details.h"
 #include "components/variations/service/variations_service.h"
 #include "content/public/browser/notification_service.h"
@@ -167,6 +168,21 @@ translate::TranslateManager* ChromeTranslateClient::GetTranslateManager() {
   return translate_manager_.get();
 }
 
+// TODO(rogerm): This code can be moved into TranslateManager.
+bool ChromeTranslateClient::RecordTranslateEvent(
+    const metrics::TranslateEventProto& translate_event) {
+  if (translate::TranslateRanker::IsEnabled()) {

[Alexei Svitkine (slow), 2016/10/12 15:21:58]

Nit: Can this code be simplified to remove this, if GetInstance() returns null
when it's disabled? Or are both needed to avoid some DCHECK?

Same for other places where you check both. Imho, if you document semantics of
GetInstance() to return null when not enabled, I think you should remove the
extra IsEnabled() to simplify the code.

[hamelphi, 2016/10/12 16:17:21]

I was just chatting about this with Roger. IsEnabled is related to whether or
not we should query or enforce the Ranker, which is not directly related to
logging, we may want to log stuff without querying the ranker for some reason.
What we need here is another flag for TranslateRanker "IsLoggingEnabled" to
control the logging of TranslateEvents independently of querying ranker and
enforcing it. Added it.

+    translate::TranslateRanker* translate_ranker =
+        translate::TranslateRanker::GetInstance();
+    if (translate_ranker != nullptr) {
+      translate_ranker->RecordTranslateEvent(translate_event);
+      return true;
+    }
+  }
+  return false;
+}
+
+
 void ChromeTranslateClient::ShowTranslateUI(
     translate::TranslateStep step,
     const std::string& source_language,