diff --git a/quiche/quic/core/quic_stream_sequencer.cc b/quiche/quic/core/quic_stream_sequencer.cc
index fa76841..540c8c7 100644
--- a/quiche/quic/core/quic_stream_sequencer.cc
+++ b/quiche/quic/core/quic_stream_sequencer.cc
@@ -297,15 +297,18 @@
   return NumBytesConsumed() + NumBytesBuffered() >= close_offset_;
 }
 
-const std::string QuicStreamSequencer::DebugString() const {
+std::string QuicStreamSequencer::DebugString() const {
   // clang-format off
-  return absl::StrCat("QuicStreamSequencer:",
-                "\n  bytes buffered: ", NumBytesBuffered(),
-                "\n  bytes consumed: ", NumBytesConsumed(),
-                "\n  has bytes to read: ", HasBytesToRead() ? "true" : "false",
-                "\n  frames received: ", num_frames_received(),
-                "\n  close offset bytes: ", close_offset_,
-                "\n  is closed: ", IsClosed() ? "true" : "false");
+  return absl::StrCat(
+      "QuicStreamSequencer:  bytes buffered: ", NumBytesBuffered(),
+      "\n  bytes consumed: ", NumBytesConsumed(),
+      "\n  first missing byte: ", buffered_frames_.FirstMissingByte(),
+      "\n  next expected byte: ", buffered_frames_.NextExpectedByte(),
+      "\n  received frames: ", buffered_frames_.ReceivedFramesDebugString(),
+      "\n  has bytes to read: ", HasBytesToRead() ? "true" : "false",
+      "\n  frames received: ", num_frames_received(),
+      "\n  close offset bytes: ", close_offset_,
+      "\n  is closed: ", IsClosed() ? "true" : "false");
   // clang-format on
 }
 
diff --git a/quiche/quic/core/quic_stream_sequencer.h b/quiche/quic/core/quic_stream_sequencer.h
index 9953c75..027b2e0 100644
--- a/quiche/quic/core/quic_stream_sequencer.h
+++ b/quiche/quic/core/quic_stream_sequencer.h
@@ -162,7 +162,7 @@
   void set_stream(StreamInterface* stream) { stream_ = stream; }
 
   // Returns string describing internal state.
-  const std::string DebugString() const;
+  std::string DebugString() const;
 
  private:
   friend class test::QuicStreamSequencerPeer;
diff --git a/quiche/quic/core/quic_stream_sequencer_buffer.h b/quiche/quic/core/quic_stream_sequencer_buffer.h
index 4540db1..9b36ee1 100644
--- a/quiche/quic/core/quic_stream_sequencer_buffer.h
+++ b/quiche/quic/core/quic_stream_sequencer_buffer.h
@@ -159,6 +159,15 @@
   // Returns number of bytes available to be read out.
   size_t ReadableBytes() const;
 
+  // Returns offset of first missing byte.
+  QuicStreamOffset FirstMissingByte() const;
+
+  // Returns offset of highest received byte + 1.
+  QuicStreamOffset NextExpectedByte() const;
+
+  // Return all received frames as a string.
+  std::string ReceivedFramesDebugString() const;
+
  private:
   friend class test::QuicStreamSequencerBufferPeer;
 
@@ -198,15 +207,6 @@
   // Get the index of the logical 1st block to start next read.
   size_t NextBlockToRead() const;
 
-  // Returns offset of first missing byte.
-  QuicStreamOffset FirstMissingByte() const;
-
-  // Returns offset of highest received byte + 1.
-  QuicStreamOffset NextExpectedByte() const;
-
-  // Return all received frames as a string.
-  std::string ReceivedFramesDebugString() const;
-
   // Resize blocks_ if more blocks are needed to accomodate bytes before
   // next_expected_byte.
   void MaybeAddMoreBlocks(QuicStreamOffset next_expected_byte);