[Cronet] Remove CronetEngine.Builder JSON serial/deserialization APIs

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.os.Build;
 import android.os.ConditionVariable;
 import android.os.Handler;
 import android.os.Looper;
@@ skipping 55 matching lines @@
             new ObserverList<NetworkQualityRttListener>();
 
     @GuardedBy("mNetworkQualityLock")
     private final ObserverList<NetworkQualityThroughputListener> mThroughputListenerList =
             new ObserverList<NetworkQualityThroughputListener>();
 
     @UsedByReflection("CronetEngine.java")
     public CronetUrlRequestContext(CronetEngine.Builder builder) {
         CronetLibraryLoader.ensureInitialized(builder.getContext(), builder);
         nativeSetMinLogLevel(getLoggingLevel());
-        mUrlRequestContextAdapter = nativeCreateRequestContextAdapter(builder.toString());
+        mUrlRequestContextAdapter = nativeCreateRequestContextAdapter(builder.toJSONString());
         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
@@ skipping 326 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);
 }