Translate: move UMA related code in TranslateManager to TranslateManagerMetrics

chrome/browser/translate/translate_manager_metrics.cc

 // 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.
 
 #include "chrome/browser/translate/translate_manager_metrics.h"
 
+#include "base/basictypes.h"
 #include "base/metrics/histogram.h"
 
 namespace {
 
-const char kTranslateInitiationStatus[] = "Translate.InitiationStatus";
+// Constant string values to indicate UMA names. All entries should have
+// a corresponding index in MetricsNameIndex and an entry in |kMetricsEntries|.
+const char kTranslateInitiationStatus[] =
+    "Translate.InitiationStatus";
+const char kTranslateReportLanguageDetectionError[] =
+    "Translate.ReportLanguageDetectionError";
+const char kTranslateServerReportedUnsupportedLanguage[] =
+    "Translate.ServerReportedUnsupportedLanguage";
+
+struct MetricsEntry {
+  TranslateManagerMetrics::MetricsNameIndex index;
+  const char* const name;
+};
+
+// This entry table should be updated when new UMA items are added.
+const MetricsEntry kMetricsEntries[] = {
+  { TranslateManagerMetrics::UMA_INITIATION_STATUS,
+    kTranslateInitiationStatus },
+  { TranslateManagerMetrics::UMA_LANGUAGE_DETECTION_ERROR,
+    kTranslateReportLanguageDetectionError },
+  { TranslateManagerMetrics::UMA_SERVER_REPORTED_UNSUPPORTED_LANGUAGE,
+    kTranslateServerReportedUnsupportedLanguage },
+};
+
+COMPILE_ASSERT(arraysize(kMetricsEntries) == TranslateManagerMetrics::UMA_MAX,
+               arraysize_of_kMetricsEntries_should_be_UMA_MAX);
 
 }  // namespace
 
 namespace TranslateManagerMetrics {
 
 void ReportInitiationStatus(InitiationStatusType type) {
   UMA_HISTOGRAM_ENUMERATION(kTranslateInitiationStatus,
                             type,
                             INITIATION_STATUS_MAX);
 }
 
-const char* GetMetricsName(MetricsNameIndex index) {
-  const char* names[] = {
-    kTranslateInitiationStatus,
-  };
-  CHECK(index < UMA_MAX);
-  return names[index];
+void ReportLanguageDetectionError() {
+  UMA_HISTOGRAM_COUNTS(kTranslateReportLanguageDetectionError, 1);
 }
 
-// TODO(toyoshim): Move UMA related code in TranslateManager to
-// TranslateManagerMetrics.
+void ReportUnsupportedLanguage() {
+  UMA_HISTOGRAM_COUNTS(kTranslateServerReportedUnsupportedLanguage, 1);
+}
+
+const char* GetMetricsName(MetricsNameIndex index) {
+  for (size_t i = 0; i < arraysize(kMetricsEntries); ++i) {
+    if (kMetricsEntries[i].index == index)
+      return kMetricsEntries[i].name;
+  }
+  NOTREACHED();
+  return NULL;
+}
 
 }  // namespace TranslateManagerMetrics