Upstream changes for NetworkQualityProvider

chrome/browser/android/net/network_quality_provider.h

+// Copyright 2015 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.

[bengr, 2015/07/21 00:06:48]

Add a blank line.

[tbansal1, 2015/07/21 16:18:25]

Done.

+#ifndef CHROME_BROWSER_ANDROID_NET_NETWORK_QUALITY_PROVIDER_H_
+#define CHROME_BROWSER_ANDROID_NET_NETWORK_QUALITY_PROVIDER_H_
+
+#include <jni.h>
+
+#include "base/android/scoped_java_ref.h"
+#include "base/macros.h"
+#include "base/memory/weak_ptr.h"
+#include "base/threading/thread_checker.h"
+#include "base/time/time.h"
+
+// Native class that calls Java code exposed by
+// NetworkQualityProviderHelper.java.
+class NetworkQualityProvider {
+ public:
+  // Constructs and initializes the underlying provider.
+  NetworkQualityProvider();
+
+  virtual ~NetworkQualityProvider();
+
+  // Returns true only if network quality estimate is available.
+  bool IsEstimateAvailable();
+
+  // Returns the expected RTT duration.
+  // Returns base::TimeDelta() if the estimate is unavailable.
+  base::TimeDelta GetRTT();
+
+  // Returns the expected downstream throughput (in Kbps).
+  // Returns 0 if the estimate is unavailable.

[bengr, 2015/07/21 00:06:48]

Why not return -1. 0 is a valid estimate, no?

[tbansal1, 2015/07/21 16:18:25]

good point, rewrote.

+  int GetDownstreamThroughputKbps();
+
+  // Returns the expected upstream throughput (in Kbps).
+  // Returns 0 if the estimate is unavailable.

[bengr, 2015/07/21 00:06:48]

Same here.

[tbansal1, 2015/07/21 16:18:25]

Done.

+  int GetUpstreamThroughputKbps();
+
+  // Returns time since network quality was last updated.
+  // Return value should be discarded if the estimate is unavailable.

[bengr, 2015/07/21 00:06:48]

You could assert that IsEstimateAvailable is called, or you could do:

bool GetTimeSinceLastUpdate(base::TimeDelta* time_delta);

and return false if unavailable. Same for all the other methods.

[tbansal1, 2015/07/21 16:18:25]

Done.

+  base::TimeDelta GetTimeSinceLastUpdate();
+
+ private:
+  base::android::ScopedJavaGlobalRef<jobject> j_network_quality_provider_;
+
+  base::ThreadChecker thread_checker_;
+
+  DISALLOW_COPY_AND_ASSIGN(NetworkQualityProvider);
+};
+
+bool RegisterNetworkQualityProvider(JNIEnv* env);
+
+#endif  // CHROME_BROWSER_ANDROID_NET_NETWORK_QUALITY_PROVIDER_H_