Implement timing metrics for UrlRequest

components/cronet/android/java/src/org/chromium/net/impl/CronetUrlRequestContext.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.impl;
 
 import android.content.Context;
 import android.os.Build;
 import android.os.ConditionVariable;
 import android.os.Handler;
@@ skipping 64 matching lines @@
     private boolean mNetworkQualityEstimatorEnabled;
 
     /**
      * Locks operations on network quality listeners, because listener
      * addition and removal may occur on a different thread from notification.
      */
     private final Object mNetworkQualityLock = new Object();
 
     /**
      * Locks operations on the list of RequestFinishedInfo.Listeners, because operations can happen
-     * on any thread.
+     * on any thread. This should be used for fine-grained locking only. In particular, don't call
+     * any UrlRequest methods that acquire mUrlRequestAdapterLock while holding this lock.
      */
     private final Object mFinishedListenerLock = new Object();
 
     /**
      * Current effective connection type as computed by the network quality
      * estimator.
      */
     @GuardedBy("mNetworkQualityLock")
     private int mEffectiveConnectionType = EffectiveConnectionType.TYPE_UNKNOWN;
 
@@ skipping 324 matching lines @@
         }
     }
 
     @Override
     public void removeRequestFinishedListener(RequestFinishedInfo.Listener listener) {
         synchronized (mFinishedListenerLock) {
             mFinishedListenerList.remove(listener);
         }
     }
 
+    boolean hasRequestFinishedListener() {
+        synchronized (mFinishedListenerLock) {
+            return !mFinishedListenerList.isEmpty();
+        }
+    }
+
     @Override
     public URLConnection openConnection(URL url) {
         return openConnection(url, Proxy.NO_PROXY);
     }
 
     @Override
     public URLConnection openConnection(URL url, Proxy proxy) {
         if (proxy.type() != Proxy.Type.DIRECT) {
             throw new UnsupportedOperationException();
         }
@@ skipping 193 matching lines @@
     @NativeClassQualifiedName("CronetURLRequestContextAdapter")
     private native void nativeProvideRTTObservations(long nativePtr, boolean should);
 
     @NativeClassQualifiedName("CronetURLRequestContextAdapter")
     private native void nativeProvideThroughputObservations(long nativePtr, boolean should);
 
     public boolean isNetworkThread(Thread thread) {
         return thread == mNetworkThread;
     }
 }