Exposing NQE on the Browser UI thread

chrome/browser/net/nqe/ui_network_quality_estimator_service.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 CHROME_BROWSER_NET_NQE_UI_NETWORK_QUALITY_ESTIMATOR_SERVICE_H_
+#define CHROME_BROWSER_NET_NQE_UI_NETWORK_QUALITY_ESTIMATOR_SERVICE_H_
+
+#include <memory>
+
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
+#include "base/single_thread_task_runner.h"
+#include "components/keyed_service/core/keyed_service.h"
+#include "net/nqe/network_quality_estimator.h"
+
+class Profile;
+
+namespace chrome_browser_net {
+
+// UI service to determine the current EffectiveConnectionType.
+class UINetworkQualityEstimatorService : public KeyedService {
+ public:
+  explicit UINetworkQualityEstimatorService(Profile* profile);
+  ~UINetworkQualityEstimatorService() override;
+
+  // KeyedService implementation:
+  void Shutdown() override;
+
+  // Called when the EffectiveConnectionType has updated to |type|.

[mmenke, 2016/07/14 19:10:12]

May want to mention NCN::GetConnectionType, any how this is different, so people
don't have to dig deeper to figure out what this actually does.

[RyanSturm, 2016/07/14 21:42:12]

Done.

+  void EffectiveConnectionTypeChanged(
+      net::NetworkQualityEstimator::EffectiveConnectionType type);

[mmenke, 2016/07/14 19:10:12]

methods that are only called by inner classes (IONetworkQualityObserver) should
be private.

[RyanSturm, 2016/07/14 21:42:12]

Done.

+
+  // Creates |io_observer_|, and posts a task to initialize it.

[mmenke, 2016/07/14 19:10:12]

See comment about getting rid of this.  More generally, io_observer_ isn't
really a part of the public API, so probably best not to mention it in
documentation of public methods.

[RyanSturm, 2016/07/14 21:42:12]

Done.

+  void Initialize(
+      const scoped_refptr<base::SingleThreadTaskRunner>& ui_task_runner,
+      const scoped_refptr<base::SingleThreadTaskRunner>& io_task_runner);
+
+  // The current EffectiveConnectionType.
+  net::NetworkQualityEstimator::EffectiveConnectionType type() const;

[mmenke, 2016/07/14 19:10:12]

Since this isn't inlined, GetType, maybe?

[RyanSturm, 2016/07/14 21:42:12]

Done.

+
+ private:
+  class IONetworkQualityObserver;
+
+  // The current EffectiveConnectionType.
+  net::NetworkQualityEstimator::EffectiveConnectionType type_;
+
+  scoped_refptr<base::SingleThreadTaskRunner> io_task_runner_;
+
+  // IO thread based observer that is owned by this service. Created on the UI
+  // thread, but used and deleted on the IO thread.
+  IONetworkQualityObserver* io_observer_;
+  base::ThreadChecker thread_checker_;
+
+  base::WeakPtrFactory<UINetworkQualityEstimatorService> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(UINetworkQualityEstimatorService);
+};
+
+}  // namespace chrome_browser_net
+
+#endif  // CHROME_BROWSER_NET_NQE_UI_NETWORK_QUALITY_ESTIMATOR_SERVICE_H_