diff --git a/quic/core/quic_session.h b/quic/core/quic_session.h
index 1d6534f..baf3a14 100644
--- a/quic/core/quic_session.h
+++ b/quic/core/quic_session.h
@@ -251,6 +251,17 @@
   // Implement StreamDelegateInterface.
   void OnStreamError(QuicErrorCode error_code,
                      std::string error_details) override;
+  // Sets priority in the write blocked list.
+  void RegisterStreamPriority(
+      QuicStreamId id,
+      bool is_static,
+      const spdy::SpdyStreamPrecedence& precedence) override;
+  // Clears priority from the write blocked list.
+  void UnregisterStreamPriority(QuicStreamId id, bool is_static) override;
+  // Updates priority on the write blocked list.
+  void UpdateStreamPriority(
+      QuicStreamId id,
+      const spdy::SpdyStreamPrecedence& new_precedence) override;
 
   // Called by streams when they want to write data to the peer.
   // Returns a pair with the number of bytes consumed from data, and a boolean
@@ -271,20 +282,6 @@
   virtual void OnCryptoHandshakeMessageReceived(
       const CryptoHandshakeMessage& message);
 
-  // Called by the stream on creation to set priority in the write blocked list.
-  virtual void RegisterStreamPriority(
-      QuicStreamId id,
-      bool is_static,
-      const spdy::SpdyStreamPrecedence& precedence);
-  // Called by the stream on deletion to clear priority from the write blocked
-  // list.
-  virtual void UnregisterStreamPriority(QuicStreamId id, bool is_static);
-  // Called by the stream on SetPriority to update priority on the write blocked
-  // list.
-  virtual void UpdateStreamPriority(
-      QuicStreamId id,
-      const spdy::SpdyStreamPrecedence& new_precedence);
-
   // Returns mutable config for this session. Returned config is owned
   // by QuicSession.
   QuicConfig* config();
diff --git a/quic/core/quic_stream.cc b/quic/core/quic_stream.cc
index 6dcbd36..ffbc7aa 100644
--- a/quic/core/quic_stream.cc
+++ b/quic/core/quic_stream.cc
@@ -366,7 +366,7 @@
     CloseWriteSide();
   }
   if (type_ != CRYPTO) {
-    session_->RegisterStreamPriority(id, is_static_, precedence_);
+    stream_delegate_->RegisterStreamPriority(id, is_static_, precedence_);
   }
 }
 
@@ -378,8 +378,8 @@
         << send_buffer_.stream_bytes_outstanding()
         << ", fin_outstanding: " << fin_outstanding_;
   }
-  if (session_ != nullptr && type_ != CRYPTO) {
-    session_->UnregisterStreamPriority(id(), is_static_);
+  if (stream_delegate_ != nullptr && type_ != CRYPTO) {
+    stream_delegate_->UnregisterStreamPriority(id(), is_static_);
   }
 }
 
@@ -551,7 +551,7 @@
 
   MaybeSendPriorityUpdateFrame();
 
-  session_->UpdateStreamPriority(id(), precedence);
+  stream_delegate_->UpdateStreamPriority(id(), precedence);
 }
 
 void QuicStream::WriteOrBufferData(
diff --git a/quic/core/stream_delegate_interface.h b/quic/core/stream_delegate_interface.h
index 2616f13..81ec92c 100644
--- a/quic/core/stream_delegate_interface.h
+++ b/quic/core/stream_delegate_interface.h
@@ -7,6 +7,7 @@
 
 #include <cstddef>
 #include "net/third_party/quiche/src/quic/core/quic_types.h"
+#include "net/third_party/quiche/src/spdy/core/spdy_protocol.h"
 
 namespace quic {
 
@@ -19,13 +20,23 @@
   // Called when the stream has encountered errors that it can't handle.
   virtual void OnStreamError(QuicErrorCode error_code,
                              std::string error_details) = 0;
-
   // Called when the stream needs to write data.
   virtual QuicConsumedData WritevData(QuicStream* stream,
                                       QuicStreamId id,
                                       size_t write_length,
                                       QuicStreamOffset offset,
                                       StreamSendingState state) = 0;
+  // Called on stream creation.
+  virtual void RegisterStreamPriority(
+      QuicStreamId id,
+      bool is_static,
+      const spdy::SpdyStreamPrecedence& precedence) = 0;
+  // Called on stream destruction to clear priority.
+  virtual void UnregisterStreamPriority(QuicStreamId id, bool is_static) = 0;
+  // Called by the stream on SetPriority to update priority.
+  virtual void UpdateStreamPriority(
+      QuicStreamId id,
+      const spdy::SpdyStreamPrecedence& new_precedence) = 0;
 };
 
 }  // namespace quic