tree bbd3c51330ec3411c9db0435fa13916d29ee7b22
parent dd4cd5eecd0506e7c29857ed7c1cd0fdfed7c0f7
author bnc <bnc@google.com> 1657651114 -0700
committer Copybara-Service <copybara-worker@google.com> 1657651215 -0700

Add BalsaVisitorInterface::OnHeader().

This method is called as soon as each header is parsed.  This allows embedders
to validate headers and potentially signal errors earlier.  The motivation for
this new method is Http1ServerConnectionImplTest.HeaderInvalidCharsRejection
in Envoy, see
https://sourcegraph.com/github.com/envoyproxy/envoy@4fd31f2/-/blob/test/common/http/http1/codec_impl_test.cc?L1115-1134.
This test does not include the end of the header block, therefore
BalsaVisitorInterface::ProcessHeaders() is never called.  With this new method
BalsaParser in Envoy will be able to validate the headers and make this test
pass.
PiperOrigin-RevId: 460514650