Use IsStreamError() and friends gMock matchers in a few tests.
gfe-relnote: n/a, test-only change.
PiperOrigin-RevId: 282776774
Change-Id: I5a8ac676cbc01c9999115f2d8f1ba54cfb28d1cb
QUICHE (QUIC, Http/2, Etc) is Google‘s implementation of QUIC and related protocols. It powers Chromium as well as Google’s QUIC servers and some other projects.