[Cronet] Use Context's ClassLoader to load Cronet

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

 // Copyright 2015 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.annotation.SuppressLint;
 import android.content.Context;
 import android.net.http.HttpResponseCache;
 import android.support.annotation.IntDef;
@@ skipping 1089 matching lines @@
      *
      * @return an {@link URLStreamHandlerFactory} instance implemented by this
      *         CronetEngine.
      */
     public abstract URLStreamHandlerFactory createURLStreamHandlerFactory();
 
     private static CronetEngine createCronetEngine(Builder builder) {
         CronetEngine cronetEngine = null;
         try {
             Class<? extends CronetEngine> engineClass =
-                    CronetEngine.class.getClassLoader()
+                    builder.getContext()
+                            .getClassLoader()
                             .loadClass(CRONET_URL_REQUEST_CONTEXT)
                             .asSubclass(CronetEngine.class);
             Constructor<? extends CronetEngine> constructor =
                     engineClass.getConstructor(Builder.class);
             CronetEngine possibleEngine = constructor.newInstance(builder);
             if (possibleEngine.isEnabled()) {
                 cronetEngine = possibleEngine;
             }
         } catch (ClassNotFoundException e) {
             // Leave as null.
@@ skipping 155 matching lines @@
      * @hide as it's a prototype.
      */
     public interface RequestFinishedListener {
         /**
          * Invoked with request info.
          * @param requestInfo {@link UrlRequestInfo} for finished request.
          */
         void onRequestFinished(UrlRequestInfo requestInfo);
     }
 }