Merge pull request #10720 from ctiller/trickle_stall

src/core/ext/transport/chttp2/transport/chttp2_transport.c

src/core/ext/transport/chttp2/transport/internal.h

src/core/ext/transport/chttp2/transport/parsing.c

src/core/ext/transport/chttp2/transport/writing.c

src/core/lib/transport/bdp_estimator.c

src/core/lib/transport/bdp_estimator.h

test/core/transport/bdp_estimator_test.c

test/core/util/trickle_endpoint.c

test/core/util/trickle_endpoint.h

test/cpp/microbenchmarks/BUILD

test/cpp/microbenchmarks/bm_fullstack_trickle.cc

tools/profiling/microbenchmarks/bm_diff.py