Modify TestRequestFinishedListener to block for finished requests

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

 // Copyright 2016 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 static junit.framework.Assert.assertNotNull;
 import static junit.framework.Assert.assertNull;
 
+import android.os.ConditionVariable;
+
 import java.util.LinkedList;
 import java.util.NoSuchElementException;
 import java.util.concurrent.Executor;
+import java.util.concurrent.Executors;
 
 /**
  * Classes which are useful for testing Cronet's metrics implementation and are needed in more than
  * one test file.
  */
 public class MetricsTestUtil {
     /**
-     * Executor which runs tasks only when told to with runAllTasks().
-     */
+      * Executor which runs tasks only when told to with runAllTasks().
+      */
     public static class TestExecutor implements Executor {
         private final LinkedList<Runnable> mTaskQueue = new LinkedList<Runnable>();
 
         @Override
         public void execute(Runnable task) {
             mTaskQueue.add(task);
         }
 
         public void runAllTasks() {
             try {
                 while (mTaskQueue.size() > 0) {
                     mTaskQueue.remove().run();
                 }
             } catch (NoSuchElementException e) {
                 throw new RuntimeException("Task was removed during iteration", e);
             }
         }
     }
 
     /**
      * RequestFinishedInfo.Listener for testing, which saves the RequestFinishedInfo
      */
     public static class TestRequestFinishedListener extends RequestFinishedInfo.Listener {
         private RequestFinishedInfo mRequestInfo;
+        private ConditionVariable mBlock;
+        private int mNumExpectedRequests = -1;
 
         public TestRequestFinishedListener(Executor executor) {
             super(executor);
         }
 
+        public TestRequestFinishedListener(int numExpectedRequests) {
+            super(Executors.newSingleThreadExecutor());
+            mNumExpectedRequests = numExpectedRequests;
+            mBlock = new ConditionVariable();
+        }
+
+        public TestRequestFinishedListener() {
+            super(Executors.newSingleThreadExecutor());
+            mNumExpectedRequests = 1;
+            mBlock = new ConditionVariable();
+        }
+
         public RequestFinishedInfo getRequestInfo() {
             return mRequestInfo;
         }
 
         @Override
         public void onRequestFinished(RequestFinishedInfo requestInfo) {
             assertNull("onRequestFinished called repeatedly", mRequestInfo);
             assertNotNull(requestInfo);
             mRequestInfo = requestInfo;
+            mNumExpectedRequests--;
+            if (mNumExpectedRequests == 0) {
+                mBlock.open();
+            }
+        }
+
+        public void blockUntilDone() {
+            mBlock.block();
         }
     }
 }