Revert "Quiche merge for Sept 11, 2020."

This reverts commit 629c4109.

Reason for revert: regression on cronet_perf_tests, reverting to confirm if this CL was the cause:
https://chromeperf.appspot.com/group_report?keys=agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDIvO-0lgoM
https://chromeperf.appspot.com/group_report?keys=agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDI_IX5rwkM
https://chromeperf.appspot.com/group_report?keys=agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDI_Nq_rgsM
https://chromeperf.appspot.com/group_report?keys=agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDI_KezuwsM

Original change's description:
> Quiche merge for Sept 11, 2020.
> 
> 
> Roll src/net/third_party/quiche/src/ 5c52ad843..0c20b03c8 (3 commits)
> 
> https://quiche.googlesource.com/quiche.git/+log/5c52ad843f8a..0c20b03c83cc
> 
> $ git log 5c52ad843..0c20b03c8 --date=short --no-merges --format='%ad %ae %s'
> 2020-09-10 renjietang deprecate gfe2_reloadable_flag_quic_do_not_use_stream_map.
> 2020-09-10 renjietang deprecate gfe2_reloadable_flag_quic_remove_streams_waiting_for_acks.
> 2020-09-10 bnc Use IETF application error codes for STOP_SENDING frames.
> 
> Created with:
>   roll-dep src/net/third_party/quiche/src src/third_party/quic_trace/src
> 
> R=​dschinazi@chromium.org
> 
> Change-Id: Iba8427627fcbfd7417a0d619f80f8b139c153cf6
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2404718
> Auto-Submit: Ian Swett <ianswett@chromium.org>
> Commit-Queue: David Schinazi <dschinazi@chromium.org>
> Reviewed-by: David Schinazi <dschinazi@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#806254}

TBR=ianswett@chromium.org,dschinazi@chromium.org

Change-Id: I178b3341725551de6012eec906ba6768089a309f
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2406391Reviewed-by: Matt Mueller <mattm@chromium.org>
Commit-Queue: Matt Mueller <mattm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#806375}

DEPS

@@ -322,7 +322,7 @@ 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': '0c20b03c83ccf22ca71935361388c71b91366f62',
+  'quiche_revision': '5c52ad843f8a33546cc17f4e7f05e6ab0df92c43',
   # 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.

net/quic/quic_flags_list.h

@@ -284,6 +284,14 @@ QUIC_FLAG(
 // If true, disable QUIC version h3-29.
 QUIC_FLAG(bool, FLAGS_quic_reloadable_flag_quic_disable_version_draft_29, false)
 
+// If true, improve Bbr2Sender::AdjustNetworkParameters by 1) do not inject a
+// bandwidth sample to the bandwidth filter, and 2) re-calculate pacing rate
+// after cwnd updated..
+QUIC_FLAG(
+    bool,
+    FLAGS_quic_reloadable_flag_quic_bbr2_improve_adjust_network_parameters,
+    true)
+
 // If true, try to coalesce packet of higher space with retransmissions to
 // mitigate RTT inflations.
 QUIC_FLAG(bool,
@@ -296,11 +304,28 @@ QUIC_FLAG(bool,
           FLAGS_quic_reloadable_flag_quic_record_received_min_ack_delay,
           false)
 
+// If true, QuicSession will no longer need streams_waiting_for_acks_.
+QUIC_FLAG(bool,
+          FLAGS_quic_reloadable_flag_quic_remove_streams_waiting_for_acks,
+          true)
+
+// When true, ParsedQuicVersionToString will print IETF drafts with format
+// draft29 instead of ff00001d.
+QUIC_FLAG(bool, FLAGS_quic_reloadable_flag_quic_fix_print_draft_version, true)
+
 // If true, disable blackhole detection on server side.
 QUIC_FLAG(bool,
           FLAGS_quic_reloadable_flag_quic_disable_server_blackhole_detection,
           false)
 
+// Remove ACK_DECIMATION_WITH_REORDERING mode and fast_ack_after_quiescence
+// option in QUIC received packet manager.
+QUIC_FLAG(bool, FLAGS_quic_reloadable_flag_quic_remove_unused_ack_options, true)
+
+// If true, QUIC subclasses will no longer directly access stream_map for its
+// content.
+QUIC_FLAG(bool, FLAGS_quic_reloadable_flag_quic_do_not_use_stream_map, true)
+
 // If true,
 //   server accepts GOAWAY (draft-28 behavior),
 //   client receiving GOAWAY with stream ID that is not client-initiated
@@ -321,6 +346,11 @@ QUIC_FLAG(bool, FLAGS_quic_reloadable_flag_quic_http3_goaway_new_behavior, true)
 // exists) after two PTOs.
 QUIC_FLAG(bool, FLAGS_quic_reloadable_flag_quic_revert_mtu_after_two_ptos, true)
 
+// Simplify the ACK code in quic_received_packet_manager.
+QUIC_FLAG(bool,
+          FLAGS_quic_reloadable_flag_quic_simplify_received_packet_manager_ack,
+          true)
+
 // If true, when TLPR copt is used, enable half RTT as first PTO timeout.
 QUIC_FLAG(bool, FLAGS_quic_reloadable_flag_quic_use_half_rtt_as_first_pto, true)
 
@@ -372,7 +402,7 @@ QUIC_FLAG(bool,
 // If true, QUIC will default enable MTU discovery, with a target of 1450 bytes.
 QUIC_FLAG(bool,
           FLAGS_quic_reloadable_flag_quic_enable_mtu_discovery_at_server,
-          true)
+          false)
 
 // If true, while reading an IETF quic packet, start peer migration immediately
 // when detecting the existence of any non-probing frame instead of at the end
@@ -426,14 +456,9 @@ QUIC_FLAG(bool,
 QUIC_FLAG(
     bool,
     FLAGS_quic_reloadable_flag_quic_close_connection_in_on_can_write_with_blocked_writer,
-    true)
+    false)
 
 // If true, include stream information in idle timeout connection close detail.
 QUIC_FLAG(bool,
           FLAGS_quic_reloadable_flag_quic_add_stream_info_to_idle_close_detail,
           true)
-
-// If true, use IETF QUIC application error codes in STOP_SENDING frames.
-QUIC_FLAG(bool,
-          FLAGS_quic_reloadable_flag_quic_stop_sending_uses_ietf_error_code,
-          false)