Move chromium-specific QUIC code from net/quic/chromium/ to net/quic/.

Cq-Include-Trybots: luci.chromium.try:ios-simulator-full-configs;master.tryserver.chromium.android:android_cronet_tester;master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: Ic1203515dfdb853ff076aa838bc27ff008f1b187
Reviewed-on: https://chromium-review.googlesource.com/1150614
Commit-Queue: Ryan Hamilton <rch@chromium.org>
Reviewed-by: Abhishek Arya <inferno@chromium.org>
Reviewed-by: Zhongyi Shi <zhongyi@chromium.org>
Reviewed-by: Helen Li <xunjieli@chromium.org>
Reviewed-by: Ramin Halavati <rhalavati@chromium.org>
Reviewed-by: Elly Fong-Jones <ellyjones@chromium.org>
Cr-Commit-Position: refs/heads/master@{#579959}
118 files changed