Added Network Quality Estimator Real-time interface to Cronet

components/cronet/android/java/src/org/chromium/net/NetworkQualityThroughputObserver.java

+// 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.
+
+package org.chromium.net;
+
+/**
+ * Interface to watch for observations of throughput.
+ */
+public interface NetworkQualityThroughputObserver {
+    /**
+     * Reports a new throughput observation. This is called on the network thread, so the
+     * observer should exit quickly.
+     * @param throughputKbps the downstream throughput in kilobits per second.
+     * @param whenMs the time since the epoch in milliseconds.
+     * @param source the observation source from {@link NetworkQualityObservationSource}.
+     */
+    public void onThroughputObservation(int throughputKbps, long whenMs, int source);
+}