Added Network Quality Estimator Real-time interface to Cronet

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

Index: components/cronet/android/java/src/org/chromium/net/NetworkQualityRttListener.java
diff --git a/components/cronet/android/java/src/org/chromium/net/NetworkQualityRttListener.java b/components/cronet/android/java/src/org/chromium/net/NetworkQualityRttListener.java
new file mode 100644
index 0000000000000000000000000000000000000000..381b477a0e383eb59204022959e8259a2dcd4c61
--- /dev/null
+++ b/components/cronet/android/java/src/org/chromium/net/NetworkQualityRttListener.java
@@ -0,0 +1,21 @@
+// 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 various round trip times (RTTs) at
+ * various layers of the network stack. These include RTT estimates by QUIC
+ * and TCP, as well as the time between when a URL request is sent and when
+ * the first byte of the response is received.
+ */
+public interface NetworkQualityRttListener {
+    /**
+     * Reports a new round trip time observation.
+     * @param rttMs the round trip time in milliseconds.
+     * @param whenMs milliseconds since the Epoch (January 1st 1970, 00:00:00.000).
+     * @param source the observation source from {@link NetworkQualityObservationSource}.
+     */
+    public void onRttObservation(int rttMs, long whenMs, int source);
+}