net: remove DNS certificate checking code.

net/url_request/url_request_context.cc

Index: net/url_request/url_request_context.cc
diff --git a/net/url_request/url_request_context.cc b/net/url_request/url_request_context.cc
index 142068e656db3959912c63a8e83ae5809d0a39ea..13a1b0d5e6153bff3bfab8d748711ed676106b07 100644
--- a/net/url_request/url_request_context.cc
+++ b/net/url_request/url_request_context.cc
@@ -19,7 +19,6 @@ URLRequestContext::URLRequestContext()
       host_resolver_(NULL),
       cert_verifier_(NULL),
       origin_bound_cert_service_(NULL),
-      dns_cert_checker_(NULL),
       fraudulent_certificate_reporter_(NULL),
       http_auth_handler_factory_(NULL),
       proxy_service_(NULL),
@@ -38,7 +37,6 @@ void URLRequestContext::CopyFrom(URLRequestContext* other) {
   set_host_resolver(other->host_resolver());
   set_cert_verifier(other->cert_verifier());
   set_origin_bound_cert_service(other->origin_bound_cert_service());
-  set_dns_cert_checker(other->dns_cert_checker());
   set_fraudulent_certificate_reporter(other->fraudulent_certificate_reporter());
   set_http_auth_handler_factory(other->http_auth_handler_factory());
   set_proxy_service(other->proxy_service());