When talking >=QUIC_VERSION_22, regularly send updated bandwidth

net/quic/quic_server_session.h

Index: net/quic/quic_server_session.h
diff --git a/net/quic/quic_server_session.h b/net/quic/quic_server_session.h
index 49c03373ed0357f9acdbabf8e37f13b89e00fff0..5e5db4402f628fd5c7d3f9637abbe957883f3b51 100644
--- a/net/quic/quic_server_session.h
+++ b/net/quic/quic_server_session.h
@@ -54,6 +54,10 @@ class QuicServerSession : public QuicSession {
   virtual void OnConnectionClosed(QuicErrorCode error, bool from_peer) OVERRIDE;
   virtual void OnWriteBlocked() OVERRIDE;
 
+  // Sends a server config update to the client, containing new bandwidth
+  // estimate.
+  virtual void OnCongestionWindowChange(QuicTime now) OVERRIDE;
+
   virtual ~QuicServerSession();
 
   virtual void InitializeSession(const QuicCryptoServerConfig& crypto_config);
@@ -65,6 +69,10 @@ class QuicServerSession : public QuicSession {
   // Override base class to process FEC config received from client.
   virtual void OnConfigNegotiated() OVERRIDE;
 
+  void set_serving_region(string serving_region) {
+    serving_region_ = serving_region;
+  }
+
  protected:
   // QuicSession methods:
   virtual QuicDataStream* CreateIncomingDataStream(QuicStreamId id) OVERRIDE;
@@ -86,6 +94,16 @@ class QuicServerSession : public QuicSession {
   scoped_ptr<QuicPerConnectionPacketWriter> connection_packet_writer_;
   QuicServerSessionVisitor* visitor_;
 
+  // The most recent bandwidth estimate sent to the client.
+  QuicBandwidth bandwidth_estimate_sent_to_client_;
+
+  // Text describing server location. Sent to the client as part of the bandwith
+  // estimate in the source-address token. Optional, can be left empty.
+  string serving_region_;
+
+  // Time at which we send the last SCUP to the client.
+  QuicTime last_server_config_update_time_;
+
   DISALLOW_COPY_AND_ASSIGN(QuicServerSession);
 };