Translate: move UMA related code in TranslateManager to TranslateManagerMetrics

chrome/renderer/translate/translate_helper_metrics.h

 // Copyright 2013 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.
 
 #ifndef CHROME_RENDERER_TRANSLATE_TRANSLATE_HELPER_METRICS_H_
 #define CHROME_RENDERER_TRANSLATE_TRANSLATE_HELPER_METRICS_H_
 
 #include <string>
 
 #include "base/time.h"
 
 namespace TranslateHelperMetrics {
 
 // An indexing type to query each UMA entry name via GetMetricsName() function.
-// Note: The implementation of GetMetricsName() should be updated when a new
-// entry is added here.
+// Note: |kMetricsEntries| should be updated when a new entry is added here.
 enum MetricsNameIndex {
   UMA_LANGUAGE_DETECTION,
   UMA_CONTENT_LANGUAGE,
   UMA_LANGUAGE_VERIFICATION,
   UMA_TIME_TO_BE_READY,
   UMA_TIME_TO_LOAD,
   UMA_TIME_TO_TRANSLATE,
   UMA_MAX,
 };
 
@@ skipping 42 matching lines @@
 void ReportLanguageDetectionTime(base::TimeTicks begin, base::TimeTicks end);
 
 #endif  // defined(ENABLE_LANGUAGE_DETECTION)
 
 // Gets UMA name for an entry specified by |index|.
 const char* GetMetricsName(MetricsNameIndex index);
 
 }  // namespace TranslateHelperMetrics
 
 #endif  // CHROME_RENDERER_TRANSLATE_TRANSLATE_HELPER_METRICS_H_