[Devtools] Allow User-Agent header override for Websockets

net/websockets/websocket_stream_cookie_test.cc

Index: net/websockets/websocket_stream_cookie_test.cc
diff --git a/net/websockets/websocket_stream_cookie_test.cc b/net/websockets/websocket_stream_cookie_test.cc
index 9ff71e001d9556ddacc0443050cb942bbb06dd9a..06136390e2447898c3130202031eecebc4ba862b 100644
--- a/net/websockets/websocket_stream_cookie_test.cc
+++ b/net/websockets/websocket_stream_cookie_test.cc
@@ -44,7 +44,7 @@ class TestBase : public WebSocketStreamCreateTestBase {
         WebSocketStandardRequestWithCookies(url.path(), url.host(), origin,
                                             cookie_header, std::string()),
         response_body);
-    CreateAndConnectStream(url.spec(), NoSubProtocols(), origin, nullptr);
+    CreateAndConnectStream(url.spec(), NoSubProtocols(), origin, "", nullptr);
   }
 
   std::string AddCRLFIfNotEmpty(const std::string& s) {