Add EffectiveConnectionType enum to the system profile proto

chrome/browser/metrics/network_quality_estimator_provider_impl.h

+// 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.
+
+#ifndef CHROME_BROWSER_METRICS_NETWORK_QUALITY_ESTIMATOR_PROVIDER_IMPL_H_
+#define CHROME_BROWSER_METRICS_NETWORK_QUALITY_ESTIMATOR_PROVIDER_IMPL_H_
+
+#include "base/callback.h"
+#include "base/macros.h"
+#include "base/threading/thread_checker.h"
+#include "components/metrics/net/network_metrics_provider.h"
+
+class IOThread;
+
+namespace metrics {
+
+// Implements NetworkMetricsProvider::NetworkQualityEstimatorProvider. Provides
+// NetworkQualityEstimator by querying the IOThread.
+class NetworkQualityEstimatorProviderImpl
+    : public NetworkMetricsProvider::NetworkQualityEstimatorProvider {
+ public:
+  explicit NetworkQualityEstimatorProviderImpl(IOThread* io_thread);
+  ~NetworkQualityEstimatorProviderImpl() override;
+
+ private:
+  // NetworkMetricsProvider::NetworkQualityEstimatorProvider implementation:

[Alexei Svitkine (slow), 2017/01/04 20:54:21]

Nit: For new code, I think this comment syntax is preferred:

// NetworkMetricsProvider::NetworkQualityEstimatorProvider:

[tbansal1, 2017/01/04 21:24:19]

Done.

+  scoped_refptr<base::SequencedTaskRunner> GetTaskRunner() override;
+

[Alexei Svitkine (slow), 2017/01/04 20:54:21]

Nit: Remove blank line.

[tbansal1, 2017/01/04 21:24:19]

Done.

+  void ProvideEstimator(
+      const base::Callback<void(net::NetworkQualityEstimator*)>& callback)
+      override;
+
+  IOThread* io_thread_;
+
+  base::ThreadChecker thread_checker_;
+
+  DISALLOW_COPY_AND_ASSIGN(NetworkQualityEstimatorProviderImpl);
+};
+
+}  // namespace metrics
+
+#endif  // CHROME_BROWSER_METRICS_NETWORK_QUALITY_ESTIMATOR_PROVIDER_IMPL_H_