Rename QuicSpdyStream::IsClosed() -> IsSequencerClosed().
IsClosed() is misleading because it implies both read/write sides are closed.
PiperOrigin-RevId: 328562437
Change-Id: I5259740408066fff71dd1ce57af8a003eed8a745
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.