Create and integrate a metrics service client into Blimp engine.

blimp/engine/app/blimp_metrics_service_client.h

+// Copyright 2016 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 BLIMP_ENGINE_APP_BLIMP_METRICS_SERVICE_CLIENT_H_
+#define BLIMP_ENGINE_APP_BLIMP_METRICS_SERVICE_CLIENT_H_
+
+#include <stdint.h>
+
+#include <string>
+
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+
+class PrefService;
+
+namespace net {
+class URLRequestContextGetter;
+}  // namespace net
+
+namespace blimp {
+namespace engine {
+
+void InitializeBlimpMetrics(

[Kevin M, 2016/05/03 18:13:20]

Add comments for these functions.

[Jess, 2016/05/03 19:33:17]

Done.

+    std::unique_ptr<PrefService> pref_service,
+    scoped_refptr<net::URLRequestContextGetter> request_context_getter);
+
+void FinalizeBlimpMetrics();
+
+}  // namespace engine
+}  // namespace blimp
+
+#endif  // BLIMP_ENGINE_APP_BLIMP_METRICS_SERVICE_CLIENT_H_