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

net/url_request/url_request_test_util.cc

Index: net/url_request/url_request_test_util.cc
diff --git a/net/url_request/url_request_test_util.cc b/net/url_request/url_request_test_util.cc
index eabdbd7325a0b9670dcf10697f64b13ad13534ee..a495c2b1d9f086c4bb83eb25cd1f0ff024e07be5 100644
--- a/net/url_request/url_request_test_util.cc
+++ b/net/url_request/url_request_test_util.cc
@@ -61,7 +61,8 @@ void TestURLRequestContext::Init() {
   initialized_ = true;
 
   if (!host_resolver())
-    context_storage_.set_host_resolver(new net::MockCachingHostResolver());
+    context_storage_.set_host_resolver(
+        scoped_ptr<net::HostResolver>(new net::MockCachingHostResolver()));
   if (!proxy_service())
     context_storage_.set_proxy_service(net::ProxyService::CreateDirect());
   if (!cert_verifier())