Enable NQE when Cronet Engine is built

components/cronet/android/api/src/org/chromium/net/CronetEngine.java

Index: components/cronet/android/api/src/org/chromium/net/CronetEngine.java
diff --git a/components/cronet/android/api/src/org/chromium/net/CronetEngine.java b/components/cronet/android/api/src/org/chromium/net/CronetEngine.java
index 2b82f2a8ad2fc9d2ef83cb454e3e5fcc852b602f..bd2f22401d9ab8dbdfe910ae5d20fab1eb00a4ef 100644
--- a/components/cronet/android/api/src/org/chromium/net/CronetEngine.java
+++ b/components/cronet/android/api/src/org/chromium/net/CronetEngine.java
@@ -120,6 +120,7 @@ public abstract class CronetEngine {
         private long mHttpCacheMaxSize;
         private String mExperimentalOptions;
         private long mMockCertVerifier;
+        private boolean mNetworkQualityEstimatorEnabled;
 
         /**
          * Default config enables SPDY, disables QUIC, SDCH and HTTP cache.
@@ -133,6 +134,7 @@ public abstract class CronetEngine {
             enableHTTP2(true);
             enableSDCH(false);
             enableHttpCache(HTTP_CACHE_DISABLED, 0);
+            enableNetworkQualityEstimator(false);
         }
 
         /**
@@ -604,6 +606,34 @@ public abstract class CronetEngine {
         }
 
         /**
+         * 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 value {@code true} to enable network quality estimator,
+         *            {@code false} to disable.
+         * @hide as it's a prototype.
+         * @return the builder to facilitate chaining.
+         */
+        public Builder enableNetworkQualityEstimator(boolean value) {
+            mNetworkQualityEstimatorEnabled = value;
+            return this;
+        }
+
+        /**
+         * @return true if the network quality estimator has been enabled for
+         * this builder.
+         * @hide as it's a prototype.
+         */
+        boolean networkQualityEstimatorEnabled() {
+            return mNetworkQualityEstimatorEnabled;
+        }
+
+        /**
          * Returns {@link Context} for builder.
          *
          * @return {@link Context} for builder.
@@ -803,6 +833,18 @@ public abstract class CronetEngine {
     public abstract byte[] getGlobalMetricsDeltas();
 
     /**
+     * Sets the executor which will be used to notify RequestFinished
+     *             listeners, and to notify network quality RTT listeners
+     *             that do not provide an executor.
+     * TODO(tbansal):  http://crbug.com/618034 Remove this API. In short term,
+     * once all Cronet embedders supply a valid executor with
+     * NetworkQualityRTTListener, update the above comment to reflect that
+     * {@link executor} is only used to notify RequestFinishedListeners.
+     * @hide as it's a prototype.
+     */
+    public abstract void setRequestFinishedListenerExecutor(Executor executor);
+
+    /**
      * 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,
@@ -813,22 +855,22 @@ public abstract class CronetEngine {
      * only when enabled.
      * @param executor an executor that will be used to notified all
      *            added RTT and throughput listeners.
+     * TODO(tbansal):  http://crbug.com/618034 Remove this API.
      * @hide as it's a prototype.
      */
     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.
+     * Configures the network quality estimator for testing. This must be called
+     * before round trip time and throughput listeners are added, and after the
+     * network quality estimator has been enabled.
      * @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.
+     * @param useSmallerResponses include small responses in throughput
+     * estimates.
      * @hide as it's a prototype.
      */
-    abstract void enableNetworkQualityEstimatorForTesting(
-            boolean useLocalHostRequests, boolean useSmallerResponses, Executor executor);
+    abstract void configureNetworkQualityEstimatorForTesting(
+            boolean useLocalHostRequests, boolean useSmallerResponses);
 
     /**
      * Registers a listener that gets called whenever the network quality
@@ -967,6 +1009,8 @@ public abstract class CronetEngine {
      *
      * @param listener the listener for finished requests.
      *
+     * TODO(tbansal):  http://crbug.com/618034 Remove this API, once all embedders have switched to
+     * using a request finished listener that provides its own executor.
      * @hide as it's a prototype.
      */
     public abstract void addRequestFinishedListener(RequestFinishedListener listener);
@@ -976,6 +1020,8 @@ public abstract class CronetEngine {
      *
      * @param listener the listener to remove.
      *
+     * TODO(tbansal):  http://crbug.com/618034 Remove this API, once all embedders have switched to
+     * using a request finished listener that provides its own executor.
      * @hide it's a prototype.
      */
     public abstract void removeRequestFinishedListener(RequestFinishedListener listener);
@@ -1096,9 +1142,11 @@ public abstract class CronetEngine {
     /**
      * Interface to listen for finished requests that were created via this CronetEngine instance.
      *
+     * TODO(tbansal):  http://crbug.com/618034 Remove this API, and replace it with a listener
+     * whose executor is bound to the lifetime of the listener.
      * @hide as it's a prototype.
      */
-    public interface RequestFinishedListener { // TODO(klm): Add a convenience abstract class.
+    public interface RequestFinishedListener {
         /**
          * Invoked with request info.
          * @param requestInfo {@link UrlRequestInfo} for finished request.