Integrate registry_hash_store_contents with the rest of tracked prefs.

components/user_prefs/tracked/tracked_preference_helper.cc

Index: components/user_prefs/tracked/tracked_preference_helper.cc
diff --git a/components/user_prefs/tracked/tracked_preference_helper.cc b/components/user_prefs/tracked/tracked_preference_helper.cc
index f2e6883cf8ad995c25f1cc2d4355c1464e0c8b5f..d30b303a1dbdaf20b909a63250cb4c906760928e 100644
--- a/components/user_prefs/tracked/tracked_preference_helper.cc
+++ b/components/user_prefs/tracked/tracked_preference_helper.cc
@@ -51,46 +51,50 @@ bool TrackedPreferenceHelper::IsPersonal() const {
 }
 
 void TrackedPreferenceHelper::ReportValidationResult(
-    PrefHashStoreTransaction::ValueState value_state) const {
+    PrefHashStoreTransaction::ValueState value_state,
+    const std::string& validation_type_suffix) const {
+  const char* histogram_name;
   switch (value_state) {
     case PrefHashStoreTransaction::UNCHANGED:
-      UMA_HISTOGRAM_ENUMERATION(
-          user_prefs::tracked::kTrackedPrefHistogramUnchanged, reporting_id_,
-          reporting_ids_count_);
-      return;
+      histogram_name = user_prefs::tracked::kTrackedPrefHistogramUnchanged;
+      break;
     case PrefHashStoreTransaction::CLEARED:
-      UMA_HISTOGRAM_ENUMERATION(
-          user_prefs::tracked::kTrackedPrefHistogramCleared, reporting_id_,
-          reporting_ids_count_);
-      return;
+      histogram_name = user_prefs::tracked::kTrackedPrefHistogramCleared;
+      break;
     case PrefHashStoreTransaction::SECURE_LEGACY:
-      UMA_HISTOGRAM_ENUMERATION(
-          user_prefs::tracked::kTrackedPrefHistogramMigratedLegacyDeviceId,
-          reporting_id_, reporting_ids_count_);
-      return;
+      histogram_name =
+          user_prefs::tracked::kTrackedPrefHistogramMigratedLegacyDeviceId;
+      break;
     case PrefHashStoreTransaction::CHANGED:
-      UMA_HISTOGRAM_ENUMERATION(
-          user_prefs::tracked::kTrackedPrefHistogramChanged, reporting_id_,
-          reporting_ids_count_);
-      return;
+      histogram_name = user_prefs::tracked::kTrackedPrefHistogramChanged;
+      break;
     case PrefHashStoreTransaction::UNTRUSTED_UNKNOWN_VALUE:
-      UMA_HISTOGRAM_ENUMERATION(
-          user_prefs::tracked::kTrackedPrefHistogramInitialized, reporting_id_,
-          reporting_ids_count_);
-      return;
+      histogram_name = user_prefs::tracked::kTrackedPrefHistogramInitialized;
+      break;
     case PrefHashStoreTransaction::TRUSTED_UNKNOWN_VALUE:
-      UMA_HISTOGRAM_ENUMERATION(
-          user_prefs::tracked::kTrackedPrefHistogramTrustedInitialized,
-          reporting_id_, reporting_ids_count_);
-      return;
+      histogram_name =
+          user_prefs::tracked::kTrackedPrefHistogramTrustedInitialized;
+      break;
     case PrefHashStoreTransaction::TRUSTED_NULL_VALUE:
-      UMA_HISTOGRAM_ENUMERATION(
-          user_prefs::tracked::kTrackedPrefHistogramNullInitialized,
-          reporting_id_, reporting_ids_count_);
+      histogram_name =
+          user_prefs::tracked::kTrackedPrefHistogramNullInitialized;
+      break;
+    default:
+      NOTREACHED() << "Unexpected PrefHashStoreTransaction::ValueState: "
+                   << value_state;
       return;
   }
-  NOTREACHED() << "Unexpected PrefHashStoreTransaction::ValueState: "
-               << value_state;
+
+  std::string full_histogram_name(histogram_name);
+  if (!validation_type_suffix.empty())
+    full_histogram_name.append(".").append(validation_type_suffix);
+
+  // Using FactoryGet to allow dynamic histogram names. Should be equivalent to
+  // UMA_HISTOGRAM_ENUMERATION(name, reporting_id_, reporting_ids_count_);
+  base::HistogramBase* histogram = base::LinearHistogram::FactoryGet(
+      full_histogram_name, 1, reporting_ids_count_, reporting_ids_count_ + 1,
+      base::HistogramBase::kUmaTargetedHistogramFlag);
+  histogram->Add(reporting_id_);
 }
 
 void TrackedPreferenceHelper::ReportAction(ResetAction reset_action) const {