Create Ukm ReportingService implementation.

components/metrics/data_use_tracker.cc

Index: components/metrics/data_use_tracker.cc
diff --git a/components/metrics/data_use_tracker.cc b/components/metrics/data_use_tracker.cc
index 6081facf5d6c068bdbf782c5fd05d7890e1b263b..ff21d0d710167455f519412f365565dd7bd6d93f 100644
--- a/components/metrics/data_use_tracker.cc
+++ b/components/metrics/data_use_tracker.cc
@@ -22,6 +22,34 @@ namespace {
 const int kDefaultUMAWeeklyQuotaBytes = 204800;
 const double kDefaultUMARatio = 0.05;
 
+struct CellDataUsePrefs {
+  const MetricsLogUploader::MetricServiceType service_type;
+  const char* service_name;
+  const char* pref_name;
+};
+
+const CellDataUsePrefs data_use_prefs[] = {
+    {MetricsLogUploader::UMA, "UMA", metrics::prefs::kUmaCellDataUse},
+    {MetricsLogUploader::UKM, "UKM", metrics::prefs::kUkmCellDataUse},
+};
+
+const char* GetPrefByServiceName(const std::string& service_name) {
+  for (const auto& pref : data_use_prefs) {
+    if (service_name == pref.service_name)
+      return pref.pref_name;
+  }

[Alexei Svitkine (slow), 2017/03/24 16:26:16]

Nit: Add a NOTREACHED()?

[Steven Holte, 2017/03/24 18:13:29]

It is reached, in most cases.

+  return NULL;

[Alexei Svitkine (slow), 2017/03/24 16:26:17]

nullptr

[Steven Holte, 2017/03/24 18:13:29]

Done.

+}
+
+const char* GetPrefByServiceType(
+    const MetricsLogUploader::MetricServiceType service_type) {

[Alexei Svitkine (slow), 2017/03/24 16:26:17]

Nit: No need for const on the param since it's an enum.

[Steven Holte, 2017/03/24 18:13:29]

Done.

+  for (const auto& pref : data_use_prefs) {
+    if (service_type == pref.service_type)
+      return pref.pref_name;
+  }

[Alexei Svitkine (slow), 2017/03/24 16:26:17]

Nit: Add a NOTREACHED()?

[Steven Holte, 2017/03/24 18:13:29]

It is reached, in most cases.

[Steven Holte, 2017/03/24 18:16:36]

Actually, this one probably won't be reached.

[Steven Holte, 2017/03/24 18:20:13]

Added a DCHECK for non-null return to ShouldUploadLogOnCellular, which is where
this is called.

+  return NULL;

[Alexei Svitkine (slow), 2017/03/24 16:26:16]

nullptr

[Steven Holte, 2017/03/24 18:13:29]

Done.

+}
+
 }  // namespace
 
 DataUseTracker::DataUseTracker(PrefService* local_state)
@@ -42,7 +70,9 @@ std::unique_ptr<DataUseTracker> DataUseTracker::Create(
 // static
 void DataUseTracker::RegisterPrefs(PrefRegistrySimple* registry) {
   registry->RegisterDictionaryPref(metrics::prefs::kUserCellDataUse);
-  registry->RegisterDictionaryPref(metrics::prefs::kUmaCellDataUse);
+  for (const auto& pref : data_use_prefs) {
+    registry->RegisterDictionaryPref(pref.pref_name);
+  }
 }
 
 void DataUseTracker::UpdateMetricsUsagePrefs(const std::string& service_name,
@@ -54,12 +84,18 @@ void DataUseTracker::UpdateMetricsUsagePrefs(const std::string& service_name,
     return;
 
   UpdateUsagePref(prefs::kUserCellDataUse, message_size);
-  if (service_name == "UMA")
-    UpdateUsagePref(prefs::kUmaCellDataUse, message_size);
+  const char* pref_name = GetPrefByServiceName(service_name);
+  if (pref_name)
+    UpdateUsagePref(pref_name, message_size);
 }
 
-bool DataUseTracker::ShouldUploadLogOnCellular(int log_bytes) {
+bool DataUseTracker::ShouldUploadLogOnCellular(
+    int log_bytes,
+    const MetricsLogUploader::MetricServiceType service_type) {

[Alexei Svitkine (slow), 2017/03/24 16:26:17]

Nit: Remove const

[Steven Holte, 2017/03/24 18:13:29]

Done.

   DCHECK(thread_checker_.CalledOnValidThread());
+  const char* pref_name = GetPrefByServiceType(service_type);
+  if (!pref_name)
+    return false;
 
   RemoveExpiredEntries();
 
@@ -67,7 +103,7 @@ bool DataUseTracker::ShouldUploadLogOnCellular(int log_bytes) {
   if (!GetUmaWeeklyQuota(&uma_weekly_quota_bytes))
     return true;
 
-  int uma_total_data_use = ComputeTotalDataUse(prefs::kUmaCellDataUse);
+  int uma_total_data_use = ComputeTotalDataUse(pref_name);
   int new_uma_total_data_use = log_bytes + uma_total_data_use;
   // If the new log doesn't increase the total UMA traffic to be above the
   // allowed quota then the log should be uploaded.
@@ -102,7 +138,9 @@ void DataUseTracker::UpdateUsagePref(const std::string& pref_name,
 
 void DataUseTracker::RemoveExpiredEntries() {
   DCHECK(thread_checker_.CalledOnValidThread());
-  RemoveExpiredEntriesForPref(prefs::kUmaCellDataUse);
+  for (const auto& pref : data_use_prefs) {
+    RemoveExpiredEntriesForPref(pref.pref_name);
+  }
   RemoveExpiredEntriesForPref(prefs::kUserCellDataUse);
 }