Revert of [Cronet] Remove JSON serialization of CronetEngine.Builder

components/cronet/android/java/src/org/chromium/net/ChromiumUrlRequestContext.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.Handler;
 import android.os.Looper;
 import android.os.Process;
@@ skipping 18 matching lines @@
      * Native adapter object, owned by ChromiumUrlRequestContext.
      */
     private long mChromiumUrlRequestContextAdapter;
 
     /**
      * Constructor.
      */
     protected ChromiumUrlRequestContext(
             final Context context, String userAgent, CronetEngine.Builder config) {
         CronetLibraryLoader.ensureInitialized(context, config);
-        mChromiumUrlRequestContextAdapter =
-                nativeCreateRequestContextAdapter(userAgent, getLoggingLevel(),
-                        CronetUrlRequestContext.createNativeUrlRequestContextConfig(config));
+        mChromiumUrlRequestContextAdapter = nativeCreateRequestContextAdapter(
+                userAgent, getLoggingLevel(), config.toJSONString());
         if (mChromiumUrlRequestContextAdapter == 0) {
             throw new NullPointerException("Context Adapter creation failed");
         }
         // Post a task to UI thread to init native Chromium URLRequestContext.
         // TODO(xunjieli): This constructor is not supposed to be invoked on
         // the main thread. Consider making the following code into a blocking
         // API to handle the case where we are already on main thread.
         Runnable task = new Runnable() {
             public void run() {
                 nativeInitRequestContextOnMainThread(
@@ skipping 82 matching lines @@
             loggingLevel = LOG_DEBUG;
         } else {
             loggingLevel = LOG_NONE;
         }
         return loggingLevel;
     }
 
     // Returns an instance ChromiumUrlRequestContextAdapter to be stored in
     // mChromiumUrlRequestContextAdapter.
     private native long nativeCreateRequestContextAdapter(
-            String userAgent, int loggingLevel, long config);
+            String userAgent, int loggingLevel, String config);
 
     private native void nativeReleaseRequestContextAdapter(
             long chromiumUrlRequestContextAdapter);
 
     private native void nativeInitializeStatistics();
 
     private native String nativeGetStatisticsJSON(String filter);
 
     private native void nativeStartNetLogToFile(
             long chromiumUrlRequestContextAdapter, String fileName,
             boolean logAll);
 
     private native void nativeStopNetLog(long chromiumUrlRequestContextAdapter);
 
     private native void nativeInitRequestContextOnMainThread(
             long chromiumUrlRequestContextAdapter);
 }