Deprecate flag FLAGS_quic_sequencer_buffer_retire_block_in_time.

net/quic/core/quic_stream_sequencer_buffer_test.cc

Index: net/quic/core/quic_stream_sequencer_buffer_test.cc
diff --git a/net/quic/core/quic_stream_sequencer_buffer_test.cc b/net/quic/core/quic_stream_sequencer_buffer_test.cc
index 58b418c1e303fea9580b87136d0df6da70e9d09f..9c6356ccebe06d487cf81a14fd5b77d2aea66649 100644
--- a/net/quic/core/quic_stream_sequencer_buffer_test.cc
+++ b/net/quic/core/quic_stream_sequencer_buffer_test.cc
@@ -416,10 +416,8 @@ TEST_F(QuicStreamSequencerBufferTest, Readv100Bytes) {
   EXPECT_EQ(100u, buffer_->BytesConsumed());
   EXPECT_EQ(source, string(dest, read));
   EXPECT_EQ(1u, helper_->frame_arrival_time_map()->size());
-  if (FLAGS_quic_sequencer_buffer_retire_block_in_time) {
-    // The first block should be released as its data has been read out.
-    EXPECT_EQ(nullptr, helper_->GetBlock(0));
-  }
+  // The first block should be released as its data has been read out.
+  EXPECT_EQ(nullptr, helper_->GetBlock(0));
   EXPECT_TRUE(helper_->CheckBufferInvariants());
 }