This CL integrates recent Chromium changes that were merged into https://github.com/devsisters/libquic/tree/master. It also performs minor cleanup, such as removing accidental usage of Chromium logging symbols (e.g. LOG(INFO), LOG(ERROR) instead of LOG(LS_INFO), LOG(LS_ERROR)) and using Chromium's scoped_ptr instead of rtc::scoped_ptr. BUG= Review URL: https://codereview.webrtc.org/1834233002 Cr-Commit-Position: refs/heads/master@{#12146}