Remove reference counting from HttpNetworkSession.

net/http/http_network_layer.h

Index: net/http/http_network_layer.h
diff --git a/net/http/http_network_layer.h b/net/http/http_network_layer.h
index 5ade926c3bddbfe123b391770d9a59f7e94bbe92..89ff8eb73d77efcb26b62b8242ff8430d53a4960 100644
--- a/net/http/http_network_layer.h
+++ b/net/http/http_network_layer.h
@@ -26,7 +26,8 @@ class NET_EXPORT HttpNetworkLayer
       NON_EXPORTED_BASE(public base::NonThreadSafe) {
  public:
   // Construct a HttpNetworkLayer with an existing HttpNetworkSession which
-  // contains a valid ProxyService.
+  // contains a valid ProxyService. The HttpNetworkLayer must be destroyed
+  // before |session|.
   explicit HttpNetworkLayer(HttpNetworkSession* session);
   ~HttpNetworkLayer() override;
 
@@ -41,7 +42,7 @@ class NET_EXPORT HttpNetworkLayer
   void OnResume() override;
 
  private:
-  const scoped_refptr<HttpNetworkSession> session_;
+  HttpNetworkSession* const session_;
   bool suspended_;
 
   DISALLOW_COPY_AND_ASSIGN(HttpNetworkLayer);