Refactor pooling logic into a helper method

net/http/http_response_body_drainer_unittest.cc

Index: net/http/http_response_body_drainer_unittest.cc
diff --git a/net/http/http_response_body_drainer_unittest.cc b/net/http/http_response_body_drainer_unittest.cc
index 42efa57f919e1923042c95188f34a76202c70bd1..fcf139da9f03523ad82a1106cca5920e78033265 100644
--- a/net/http/http_response_body_drainer_unittest.cc
+++ b/net/http/http_response_body_drainer_unittest.cc
@@ -16,6 +16,7 @@
 #include "net/http/http_network_session.h"
 #include "net/http/http_server_properties_impl.h"
 #include "net/http/http_stream.h"
+#include "net/http/transport_security_state.h"
 #include "net/proxy/proxy_service.h"
 #include "net/ssl/ssl_config_service_defaults.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -221,6 +222,7 @@ class HttpResponseBodyDrainerTest : public testing::Test {
     params.proxy_service = proxy_service_.get();
     params.ssl_config_service = ssl_config_service_.get();
     params.http_server_properties = http_server_properties_->GetWeakPtr();
+    params.transport_security_state = new TransportSecurityState();
     return new HttpNetworkSession(params);
   }