Create Ukm ReportingService implementation.

components/ukm/ukm_rotation_scheduler.cc

+// Copyright 2017 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 "components/ukm/ukm_rotation_scheduler.h"
+
+#include "base/metrics/histogram_macros.h"
+
+namespace ukm {
+
+UkmRotationScheduler::UkmRotationScheduler(
+    const base::Closure& upload_callback,
+    const base::Callback<base::TimeDelta(void)>& upload_interval_callback)
+    : metrics::MetricsRotationScheduler(upload_callback,
+                                        upload_interval_callback) {}
+
+UkmRotationScheduler::~UkmRotationScheduler() = default;
+
+void UkmRotationScheduler::LogMetricsInitSequence(InitSequence sequence) {
+  UMA_HISTOGRAM_ENUMERATION("UKM.InitSequence", sequence,
+                            INIT_SEQUENCE_ENUM_SIZE);
+}
+
+}  // namespace ukm