Add minimal spdy priority set by gws response header for initial cwnd bootstrapping for http2. also store spdy priority within spdydispatcher::sessiondata. no production behavior change unless we start an additional gws experiment. protected by gfe2_restart_flag_h2_adjust_initial_cwnd_by_gws.
While QUIC stores SPDY within spdy::PriorityWriteScheduler<...>, SPDY priority is stored in a map from stream_id to SessionData owned by SpdyClientDispatcher in this change because
(1) H2 uses LIFOWriteScheduler<...> by default, which ignores precedence (http://shortn/_2Ny3X9xBh6).
(2) We only need CWND bootstrapping for traffic from client, and hence only SpdyClientDispatcher populates the SPDY priority.
PiperOrigin-RevId: 316117083
Change-Id: I232e421b16edecc5f7146ce4fb36592a71a7e86f
4 files changed
