Roll src/net/third_party/quiche/src/ 8f3a57651..6270680e7 (8 commits)

https://quiche.googlesource.com/quiche.git/+log/8f3a576515ad..6270680e7eb9

$ git log 8f3a57651..6270680e7 --date=short --no-merges --format='%ad %ae %s'
2019-06-26 bnc Make QuicSpdyStream::OnStreamHeaderList() return void.
2019-06-26 bnc Make QuicSpdyStream::ParseHeaderStatusCode() static.
2019-06-26 bnc Do not call HttpDecoder::ProcessInput after error.
2019-06-26 dschinazi Update QuicEnableVersion to no longer stack flags
2019-06-25 dschinazi Update QUICHE contributing guidelines
2019-06-25 bnc Make QuicSpdyStream methods only called by HttpDecoderVisitor private.
2019-06-25 bnc Implement pause/resume in HttpDecoder.
2019-06-25 quiche-dev Add a test to ensure that a push promise to the server closes the connection.

Created with:
  roll-dep src/net/third_party/quiche/src src/third_party/quic_trace/src

Change-Id: I45b1214845231714e5658847138f630cacf88dc6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1679172
Commit-Queue: Zhongyi Shi <zhongyi@chromium.org>
Commit-Queue: Ryan Hamilton <rch@chromium.org>
Auto-Submit: Zhongyi Shi <zhongyi@chromium.org>
Reviewed-by: Ryan Hamilton <rch@chromium.org>
Cr-Commit-Position: refs/heads/master@{#672762}

DEPS

@@ -281,7 +281,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling feed
   # and whatever else without interference from each other.
-  'quiche_revision': '8f3a576515ada564d3e2b560220649f49a21dec1',
+  'quiche_revision': '6270680e7eb966c8f91df270eb3121ee6fb9b014',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling ios_webkit
   # and whatever else without interference from each other.