[Cronet] Continue UrlRequest with NULL certificate if Client cert is requested.

components/cronet/android/cronet_url_request_adapter.cc

 // 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.
 
 #include "cronet_url_request_adapter.h"
 
 #include <limits>
 #include <vector>
 
 #include "base/bind.h"
@@ skipping 239 matching lines @@
   JNIEnv* env = base::android::AttachCurrentThread();
 
   cronet::Java_CronetUrlRequest_onRedirectReceived(
       env, owner_.obj(),
       ConvertUTF8ToJavaString(env, redirect_info.new_url.spec()).obj(),
       redirect_info.status_code, GetResponseHeaders(env).obj(),
       request->GetTotalReceivedBytes());
   *defer_redirect = true;
 }
 
+void CronetURLRequestAdapter::OnCertificateRequested(
+    net::URLRequest* request,
+    net::SSLCertRequestInfo* cert_request_info) {
+  DCHECK(context_->IsOnNetworkThread());
+  // Cronet does not support client certificates.
+  request->ContinueWithCertificate(nullptr, nullptr);
+}
+
 void CronetURLRequestAdapter::OnSSLCertificateError(
     net::URLRequest* request,
     const net::SSLInfo& ssl_info,
     bool fatal) {
   DCHECK(context_->IsOnNetworkThread());
   request->Cancel();
   int net_error = net::MapCertStatusToNetError(ssl_info.cert_status);
   JNIEnv* env = base::android::AttachCurrentThread();
   cronet::Java_CronetUrlRequest_onError(
       env, owner_.obj(), net_error,
@@ skipping 118 matching lines @@
           << " on chromium request: " << initial_url_.possibly_invalid_spec();
   JNIEnv* env = base::android::AttachCurrentThread();
   cronet::Java_CronetUrlRequest_onError(
       env, owner_.obj(), net_error,
       ConvertUTF8ToJavaString(env, net::ErrorToString(net_error)).obj(),
       request->GetTotalReceivedBytes());
   return true;
 }
 
 }  // namespace cronet