Synchronize native adapter access in CronetUrlRequestContext

components/cronet/android/java/src/org/chromium/net/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;
 
 import android.content.Context;
 import android.os.Build;
 import android.os.ConditionVariable;
 import android.os.Handler;
@@ skipping 61 matching lines @@
             new ObserverList<NetworkQualityThroughputListener>();
 
     @GuardedBy("mNetworkQualityLock")
     private final ObserverList<RequestFinishedListener> mFinishedListenerList =
             new ObserverList<RequestFinishedListener>();
 
     @UsedByReflection("CronetEngine.java")
     public CronetUrlRequestContext(CronetEngine.Builder builder) {
         CronetLibraryLoader.ensureInitialized(builder.getContext(), builder);
         nativeSetMinLogLevel(getLoggingLevel());
-        mUrlRequestContextAdapter = nativeCreateRequestContextAdapter(
-                createNativeUrlRequestContextConfig(builder.getContext(), builder));
-        if (mUrlRequestContextAdapter == 0) {
-            throw new NullPointerException("Context Adapter creation failed.");
+        synchronized (mLock) {
+            mUrlRequestContextAdapter = nativeCreateRequestContextAdapter(
+                    createNativeUrlRequestContextConfig(builder.getContext(), builder));
+            if (mUrlRequestContextAdapter == 0) {
+                throw new NullPointerException("Context Adapter creation failed.");
+            }
         }
 
         // Init native Chromium URLRequestContext on main UI thread.
         Runnable task = new Runnable() {
             @Override
             public void run() {
                 synchronized (mLock) {
                     // mUrlRequestContextAdapter is guaranteed to exist until
                     // initialization on main and network threads completes and
                     // initNetworkThread is called back on network thread.
@@ skipping 406 matching lines @@
     @NativeClassQualifiedName("CronetURLRequestContextAdapter")
     private native void nativeEnableNetworkQualityEstimator(
             long nativePtr, boolean useLocalHostRequests, boolean useSmallerResponses);
 
     @NativeClassQualifiedName("CronetURLRequestContextAdapter")
     private native void nativeProvideRTTObservations(long nativePtr, boolean should);
 
     @NativeClassQualifiedName("CronetURLRequestContextAdapter")
     private native void nativeProvideThroughputObservations(long nativePtr, boolean should);
 }