Fix flaky NQE QUIC test

components/cronet/android/test/javatests/src/org/chromium/net/NQETest.java

 // Copyright 2017 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.os.ConditionVariable;
 import android.os.StrictMode;
 import android.support.test.filters.SmallTest;
 
 import org.chromium.base.Log;
 import org.chromium.base.annotations.JNINamespace;
 import org.chromium.base.annotations.SuppressFBWarnings;
 import org.chromium.base.test.util.DisabledTest;
 import org.chromium.base.test.util.Feature;
 import org.chromium.base.test.util.MetricsUtils.HistogramDelta;
 import org.chromium.net.MetricsTestUtil.TestExecutor;
@@ skipping 53 matching lines @@
     @Feature({"Cronet"})
     public void testNotEnabled() throws Exception {
         ExperimentalCronetEngine.Builder mCronetEngineBuilder =
                 new ExperimentalCronetEngine.Builder(getContext());
         final CronetTestFramework testFramework =
                 startCronetTestFrameworkWithUrlAndCronetEngineBuilder(null, mCronetEngineBuilder);
         Executor networkQualityExecutor = Executors.newSingleThreadExecutor();
         TestNetworkQualityRttListener rttListener =
                 new TestNetworkQualityRttListener(networkQualityExecutor);
         TestNetworkQualityThroughputListener throughputListener =
-                new TestNetworkQualityThroughputListener(networkQualityExecutor, null);
+                new TestNetworkQualityThroughputListener(networkQualityExecutor);
         try {
             testFramework.mCronetEngine.addRttListener(rttListener);
             fail("Should throw an exception.");
         } catch (IllegalStateException e) {
         }
         try {
             testFramework.mCronetEngine.addThroughputListener(throughputListener);
             fail("Should throw an exception.");
         } catch (IllegalStateException e) {
         }
@@ skipping 48 matching lines @@
     }
 
     @SmallTest
     @Feature({"Cronet"})
     @DisabledTest(message = "Disabled due to flaky assert. See crbug.com/710626")
     public void testQuicDisabled() throws Exception {
         ExperimentalCronetEngine.Builder mCronetEngineBuilder =
                 new ExperimentalCronetEngine.Builder(getContext());
         assert RttThroughputValues.INVALID_RTT_THROUGHPUT < 0;
         Executor listenersExecutor = Executors.newSingleThreadExecutor(new ExecutorThreadFactory());
-        ConditionVariable waitForThroughput = new ConditionVariable();
         TestNetworkQualityRttListener rttListener =
                 new TestNetworkQualityRttListener(listenersExecutor);
         TestNetworkQualityThroughputListener throughputListener =
-                new TestNetworkQualityThroughputListener(listenersExecutor, waitForThroughput);
+                new TestNetworkQualityThroughputListener(listenersExecutor);
         mCronetEngineBuilder.enableNetworkQualityEstimator(true).enableHttp2(true).enableQuic(
                 false);
         mCronetEngineBuilder.setStoragePath(CronetTestFramework.getTestStorage(getContext()));
         final CronetTestFramework testFramework =
                 startCronetTestFrameworkWithUrlAndCronetEngineBuilder(null, mCronetEngineBuilder);
         testFramework.mCronetEngine.configureNetworkQualityEstimatorForTesting(true, true, true);
 
         testFramework.mCronetEngine.addRttListener(rttListener);
         testFramework.mCronetEngine.addThroughputListener(throughputListener);
 
         HistogramDelta writeCountHistogram = new HistogramDelta("NQE.Prefs.WriteCount", 1);
         assertEquals(0, writeCountHistogram.getDelta()); // Sanity check.
 
         HistogramDelta readCountHistogram = new HistogramDelta("NQE.Prefs.ReadCount", 1);
         assertEquals(0, readCountHistogram.getDelta()); // Sanity check.
 
         TestUrlRequestCallback callback = new TestUrlRequestCallback();
         UrlRequest.Builder builder = testFramework.mCronetEngine.newUrlRequestBuilder(
                 mUrl, callback, callback.getExecutor());
         UrlRequest urlRequest = builder.build();
         urlRequest.start();
         callback.blockForDone();
 
         // Throughput observation is posted to the network quality estimator on the network thread
         // after the UrlRequest is completed. The observations are then eventually posted to
         // throughput listeners on the executor provided to network quality.
-        waitForThroughput.block();
+        throughputListener.waitUntilFirstThroughputObservationReceived();
+
+        // Wait for RTT observation (at the URL request layer) to be posted.
+        rttListener.waitUntilFirstUrlRequestRTTReceived();
+
         assertTrue(throughputListener.throughputObservationCount() > 0);
 
         // Prefs must be read at startup.
         assertTrue(readCountHistogram.getDelta() > 0);
 
         // Check RTT observation count after throughput observation has been received. This ensures
         // that executor has finished posting the RTT observation to the RTT listeners.
         assertTrue(rttListener.rttObservationCount() > 0);
 
         // NETWORK_QUALITY_OBSERVATION_SOURCE_URL_REQUEST
@@ skipping 32 matching lines @@
                 // Ignored this exception since the file will only be created when updates are
                 // flushed to the disk.
             }
         }
         assertTrue(fileContainsString("local_prefs.json", "network_qualities"));
 
         testFramework.mCronetEngine.shutdown();
         assertTrue(writeCountHistogram.getDelta() > 0);
     }
 }