Add perspective_ member for QuicStream.
This change is in favor of removing session access from stream.
gfe-relnote: no behavior change. Not protected.
PiperOrigin-RevId: 295011376
Change-Id: Ie6a9f899a52bbc1c7ae4eda149259bbc40dba95d
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.