Revert of Remove reference counting from HttpNetworkSession.

google_apis/gcm/engine/connection_factory_impl.h

Index: google_apis/gcm/engine/connection_factory_impl.h
diff --git a/google_apis/gcm/engine/connection_factory_impl.h b/google_apis/gcm/engine/connection_factory_impl.h
index a07de1266fc7d1ff228aeb7cb67b1552e9e64538..d979208af3dc517c130cf16ee10e2921c908639f 100644
--- a/google_apis/gcm/engine/connection_factory_impl.h
+++ b/google_apis/gcm/engine/connection_factory_impl.h
@@ -36,14 +36,11 @@
   // for proxy auth credentials (via its HttpAuthCache). |gcm_network_session|
   // is the network session through which GCM connections should be made, and
   // must not be the same as |http_network_session|.
-  //
-  // The caller is responsible for making sure the ConnectionFactoryImpl is
-  // destroyed before the |gcm_network_session| and |http_network_session|.
   ConnectionFactoryImpl(
       const std::vector<GURL>& mcs_endpoints,
       const net::BackoffEntry::Policy& backoff_policy,
-      net::HttpNetworkSession* gcm_network_session,
-      net::HttpNetworkSession* http_network_session,
+      const scoped_refptr<net::HttpNetworkSession>& gcm_network_session,
+      const scoped_refptr<net::HttpNetworkSession>& http_network_session,
       net::NetLog* net_log,
       GCMStatsRecorder* recorder);
   ~ConnectionFactoryImpl() override;
@@ -138,10 +135,10 @@
 
   // ---- net:: components for establishing connections. ----
   // Network session for creating new GCM connections.
-  net::HttpNetworkSession* gcm_network_session_;
+  const scoped_refptr<net::HttpNetworkSession> gcm_network_session_;
   // HTTP Network session. If set, is used for extracting proxy auth
-  // credentials. If nullptr, is ignored.
-  net::HttpNetworkSession* http_network_session_;
+  // credentials. If not set, is ignored.
+  const scoped_refptr<net::HttpNetworkSession> http_network_session_;
   // Net log to use in connection attempts.
   net::BoundNetLog bound_net_log_;
   // The current PAC request, if one exists. Owned by the proxy service.