Respect QuicAllowed policy for new streams

ios/chrome/browser/ios_chrome_io_thread.h

Index: ios/chrome/browser/ios_chrome_io_thread.h
diff --git a/ios/chrome/browser/ios_chrome_io_thread.h b/ios/chrome/browser/ios_chrome_io_thread.h
index bd1207f23153f6e42e64abce79190ef7fcd637ed..2ec2049fcd03beeed72b80770b5883fc075978dc 100644
--- a/ios/chrome/browser/ios_chrome_io_thread.h
+++ b/ios/chrome/browser/ios_chrome_io_thread.h
@@ -116,6 +116,8 @@ class IOSChromeIOThread : public web::WebThreadDelegate {
     std::unique_ptr<net::HttpServerProperties> http_server_properties;
     std::unique_ptr<net::ProxyService> system_proxy_service;
     std::unique_ptr<net::HttpNetworkSession> system_http_network_session;
+    std::unique_ptr<net::HttpNetworkSession::DynamicSharedParams>
+        http_network_session_dynamic_shared_params;
     std::unique_ptr<net::HttpTransactionFactory>
         system_http_transaction_factory;
     std::unique_ptr<net::URLRequestJobFactory> system_url_request_job_factory;