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

components/cronet/android/cronet_url_request_adapter.h

Index: components/cronet/android/cronet_url_request_adapter.h
diff --git a/components/cronet/android/cronet_url_request_adapter.h b/components/cronet/android/cronet_url_request_adapter.h
index baab62d81b553e911d0e7e322f5988a3452bc1f2..853c192fe40e99f55269f77817e6162c368669b1 100644
--- a/components/cronet/android/cronet_url_request_adapter.h
+++ b/components/cronet/android/cronet_url_request_adapter.h
@@ -28,6 +28,7 @@ class SingleThreadTaskRunner;
 namespace net {
 class HttpRequestHeaders;
 class HttpResponseHeaders;
+class SSLCertRequestInfo;
 class SSLInfo;
 class UploadDataStream;
 }  // namespace net
@@ -118,6 +119,9 @@ class CronetURLRequestAdapter : public net::URLRequest::Delegate {
   void OnReceivedRedirect(net::URLRequest* request,
                           const net::RedirectInfo& redirect_info,
                           bool* defer_redirect) override;
+  void OnCertificateRequested(
+      net::URLRequest* request,
+      net::SSLCertRequestInfo* cert_request_info) override;
   void OnSSLCertificateError(net::URLRequest* request,
                              const net::SSLInfo& ssl_info,
                              bool fatal) override;