When talking >=QUIC_VERSION_22, regularly send updated bandwidth

net/quic/quic_connection.h

Index: net/quic/quic_connection.h
diff --git a/net/quic/quic_connection.h b/net/quic/quic_connection.h
index 4d57208caef001a3868d95538db8070f738e9e8a..29fa2793bb4e54865e3bb7155910cafd62b8ed84 100644
--- a/net/quic/quic_connection.h
+++ b/net/quic/quic_connection.h
@@ -94,6 +94,9 @@ class NET_EXPORT_PRIVATE QuicConnectionVisitorInterface {
   // Called when a blocked socket becomes writable.
   virtual void OnCanWrite() = 0;
 
+  // Called when the connection experiences a change in congestion window.
+  virtual void OnCongestionWindowChange(QuicTime now) = 0;
+
   // Called to ask if the visitor wants to schedule write resumption as it both
   // has pending data to write, and is able to write (e.g. based on flow control
   // limits).
@@ -222,7 +225,8 @@ class NET_EXPORT_PRIVATE QuicConnectionHelperInterface {
 class NET_EXPORT_PRIVATE QuicConnection
     : public QuicFramerVisitorInterface,
       public QuicBlockedWriterInterface,
-      public QuicPacketGenerator::DelegateInterface {
+      public QuicPacketGenerator::DelegateInterface,
+      public QuicSentPacketManager::NetworkChangeVisitor {
  public:
   enum PacketType {
     NORMAL,
@@ -366,6 +370,10 @@ class NET_EXPORT_PRIVATE QuicConnection
   virtual QuicStopWaitingFrame* CreateStopWaitingFrame() OVERRIDE;
   virtual bool OnSerializedPacket(const SerializedPacket& packet) OVERRIDE;
 
+  // QuicSentPacketManager::NetworkChangeVisitor
+  virtual void OnCongestionWindowChange(
+      QuicByteCount congestion_window) OVERRIDE;
+
   // Called by the crypto stream when the handshake completes. In the server's
   // case this is when the SHLO has been ACKed. Clients call this on receipt of
   // the SHLO.