[net] Change factory methods for HostResolver and HostCache to return a scoped_ptr

net/tools/fetch/fetch_client.cc

Index: net/tools/fetch/fetch_client.cc
diff --git a/net/tools/fetch/fetch_client.cc b/net/tools/fetch/fetch_client.cc
index b69b2c91c432cef6c6719c7085c38b090aa0ca4d..cfb86ab4ebdabd73763b5db1c045fccecf7b440d 100644
--- a/net/tools/fetch/fetch_client.cc
+++ b/net/tools/fetch/fetch_client.cc
@@ -141,10 +141,7 @@ int main(int argc, char** argv) {
   MessageLoop loop(MessageLoop::TYPE_IO);
 
   scoped_ptr<net::HostResolver> host_resolver(
-      net::CreateSystemHostResolver(net::HostResolver::kDefaultParallelism,
-                                    net::HostResolver::kDefaultRetryAttempts,
-                                    NULL));
-
+      net::HostResolver::CreateDefaultResolver(NULL));
   scoped_ptr<net::CertVerifier> cert_verifier(
       net::CertVerifier::CreateDefault());
   scoped_ptr<net::ProxyService> proxy_service(