Deprecate FLAGS_quic_ack_decimation.

net/quic/quic_flags.cc

Index: net/quic/quic_flags.cc
diff --git a/net/quic/quic_flags.cc b/net/quic/quic_flags.cc
index 44531000619b24eed51aa3fff3e9f87a53f3c019..148aa094f2fa1ce3828a484601b6b9f2a5ec2a62 100644
--- a/net/quic/quic_flags.cc
+++ b/net/quic/quic_flags.cc
@@ -41,10 +41,6 @@ int64_t FLAGS_quic_time_wait_list_max_connections = 600000;
 // Enables server-side support for QUIC stateless rejects.
 bool FLAGS_enable_quic_stateless_reject_support = true;
 
-// If ture, allow Ack Decimation to be used for QUIC when requested by the
-// client connection option ACKD.
-bool FLAGS_quic_ack_decimation = true;
-
 // This flag is not in use, just to keep consistency for shared code.
 bool FLAGS_quic_always_log_bugs_for_tests = false;