Add a SetDoNotFragment() method to DatagramSocket, and call this for

net/socket/websocket_endpoint_lock_manager_unittest.cc

Index: net/socket/websocket_endpoint_lock_manager_unittest.cc
diff --git a/net/socket/websocket_endpoint_lock_manager_unittest.cc b/net/socket/websocket_endpoint_lock_manager_unittest.cc
index e0f479997221bf3bde129b18e2df25b960e842ca..d9016a612adf3635a27d1118c8cb9d6cdc336d7a 100644
--- a/net/socket/websocket_endpoint_lock_manager_unittest.cc
+++ b/net/socket/websocket_endpoint_lock_manager_unittest.cc
@@ -89,6 +89,8 @@ class FakeStreamSocket : public StreamSocket {
 
   int SetSendBufferSize(int32_t size) override { return ERR_FAILED; }
 
+  int SetDoNotFragment(bool do_not_fragment) override { return ERR_FAILED; }
+
  private:
   BoundNetLog bound_net_log_;