Turn on the new WebSocket implementation by default.

LayoutTests/virtual/stable/http/tests/websocket/workers/no-onmessage-in-sync-op-expected.txt

-WebSocket's message event should not be invoked while we are waiting for the result of a synchronous operation (such as WebSocket.send()) on workers.
-
-On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
-
-INFO: Waiting for two seconds to make sure we receive messages from the server.
-PASS PASS: closeEvent.wasClean is true
-PASS PASS: event.length is 9
-PASS PASS: events[0] is "Got bufferedAmount: 0"
-PASS PASS: events[1] is "Got bufferedAmount: 0"
-PASS PASS: events[2] is "Got bufferedAmount: 0"
-PASS PASS: events[3] is "Sent message: 1"
-PASS PASS: events[4] is "Sent message: 2"
-PASS PASS: events[5] is "Sent message: 3"
-PASS PASS: events[6] is "Received message: 1"
-PASS PASS: events[7] is "Received message: 2"
-PASS PASS: events[8] is "Received message: 3"
-DONE
-PASS successfullyParsed is true
-
-TEST COMPLETE
-