Added Network Quality Estimator Real-time interface to Cronet

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

 // Copyright 2014 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;
 
 import android.content.Context;
 import android.util.Log;
 
 import java.lang.reflect.Constructor;
@@ skipping 76 matching lines @@
      */
     public abstract void startNetLogToFile(String fileName, boolean logAll);
 
     /**
      * Stops NetLog logging and flushes file to disk. If a logging session is
      * not in progress, this call is ignored.
      */
     public abstract void stopNetLog();
 
     /**
+     * Enables the network quality estimator, which collects and reports
+     * measurements of round trip time (RTT) and downstream throughput at
+     * various layers of the network stack. After enabling the estimator,
+     * listeners of RTT and throughput can be added with
+     * {@link #addRttListener} and {@link #addThroughputListener} and
+     * removed with {@link #removeRttListener} and
+     * {@link #removeThroughputListener}. The estimator uses memory and CPU
+     * only when enabled.
+     * @param executor an executor that will be used to notified all
+     *            added RTT and throughput listeners.
+     */
+    public abstract void enableNetworkQualityEstimator(Executor executor);
+
+    /**
+     * Enables the network quality estimator for testing. This must be called
+     * before round trip time and throughput listeners are added. Set both
+     * boolean parameters to false for default behavior.
+     * @param useLocalHostRequests include requests to localhost in estimates.
+     * @param useSmallerResponses include small responses in throughput estimates.
+     * @param executor an {@link java.util.concurrent.Executor} on which all
+     *            listeners will be called.
+     */
+    abstract void enableNetworkQualityEstimator(
+            boolean useLocalHostRequests, boolean useSmallerResponses, Executor executor);
+
+    /**
+     * Registers an listener that gets called whenever the network quality
+     * estimator witnesses a sample round trip time. This must be called
+     * after {@link #enableNetworkQualityEstimator}. Round trip times may be
+     * recorded at various layers of the network stack, including TCP, QUIC,
+     * and at the URL request layer. The listener is called on the
+     * {@link java.util.concurrent.Executor} that is passed to
+     * {@link #enableNetworkQualityEstimator}.
+     * @param listener the listener of round trip times.
+     */
+    public abstract void addRttListener(NetworkQualityRttListener listener);
+
+    /**
+     * Removes an listener of round trip times if on the listener list. This
+     * should be called after a NetworkQualityRttListener is added in order to
+     * stop receiving observations.
+     * @param listener the listener of round trip times.
+     */
+    public abstract void removeRttListener(NetworkQualityRttListener listener);
+
+    /**
+     * Registers an listener that gets called whenever the network quality

[mef, 2015/10/01 19:02:28]

I'm not native speaker, but shouldn't "an listener" be "a listener" here and
elsewhere.

[bengr, 2015/10/01 23:14:35]

Damn search and replace. Done.

+     * estimator witnesses a sample throughput measurement. This must be called
+     * after {@link #enableNetworkQualityEstimator}. Throughput observations
+     * are computed by measuring bytes read over the active network interface
+     * at times when at least one URL response is being received. The listener
+     * is called on the {@link java.util.concurrent.Executor} that is passed to
+     * {@link #enableNetworkQualityEstimator}.
+     * @param listener the listener of throughput.
+     */
+    public abstract void addThroughputListener(NetworkQualityThroughputListener listener);
+
+    /**
+     * Removes an listener of throughput. This should be called after a
+     * NetworkQualityThroughputListener is added in order to stop receiving
+     * observations.
+     * @param listener the listener of throughput.
+     */
+    public abstract void removeThroughputListener(NetworkQualityThroughputListener listener);
+
+    /**
      * Creates a {@link UrlRequestContext} with the given
      * {@link UrlRequestContextConfig}.
      * @param context Android {@link Context}.
      * @param config context configuration.
      */
     public static UrlRequestContext createContext(Context context,
             UrlRequestContextConfig config) {
         UrlRequestContext urlRequestContext = null;
         if (config.userAgent().isEmpty()) {
             config.setUserAgent(UserAgent.from(context));
@@ skipping 30 matching lines @@
         } catch (ClassNotFoundException e) {
             // Leave as null.
         } catch (Exception e) {
             throw new IllegalStateException(
                     "Cannot instantiate: " + CRONET_URL_REQUEST_CONTEXT,
                     e);
         }
         return urlRequestContext;
     }
 }