Make Quic client more memory efficient. Protected by --quic_headers_stream_release_sequencer_buffer.

net/quic/core/quic_headers_stream.cc

Index: net/quic/core/quic_headers_stream.cc
diff --git a/net/quic/core/quic_headers_stream.cc b/net/quic/core/quic_headers_stream.cc
index 57d675f2707e46ffe503a019ef23ca8b3ad99168..2faf39e15c86004ee9f7f64cb4463c4057ed7a65 100644
--- a/net/quic/core/quic_headers_stream.cc
+++ b/net/quic/core/quic_headers_stream.cc
@@ -461,6 +461,7 @@ void QuicHeadersStream::OnDataAvailable() {
       return;
     }
     sequencer()->MarkConsumed(iov.iov_len);
+    MaybeReleaseSequencerBuffer();
   }
 }
 
@@ -569,6 +570,13 @@ void QuicHeadersStream::UpdateEnableServerPush(bool value) {
   spdy_session_->set_server_push_enabled(value);
 }
 
+void QuicHeadersStream::MaybeReleaseSequencerBuffer() {
+  if (FLAGS_quic_headers_stream_release_sequencer_buffer &&
+      spdy_session_->ShouldReleaseHeadersStreamSequencerBuffer()) {
+    sequencer()->ReleaseBufferIfEmpty();
+  }
+}
+
 bool QuicHeadersStream::OnDataFrameHeader(QuicStreamId stream_id,
                                           size_t length,
                                           bool fin) {