Sent QUIC "PING" frames when a stream is open and the connection

net/quic/quic_session.h

Index: net/quic/quic_session.h
diff --git a/net/quic/quic_session.h b/net/quic/quic_session.h
index 76fb274078b18b9d6d9688fe9d66f3b5c89165aa..ca2189a3a119114419a97945a8f22a656b6c3705 100644
--- a/net/quic/quic_session.h
+++ b/net/quic/quic_session.h
@@ -73,6 +73,7 @@ class NET_EXPORT_PRIVATE QuicSession : public QuicConnectionVisitorInterface {
   virtual void OnCanWrite() OVERRIDE;
   virtual bool HasPendingWrites() const OVERRIDE;
   virtual bool HasPendingHandshake() const OVERRIDE;
+  virtual bool HasOpenDataStreams() const OVERRIDE;
 
   // Called by the headers stream when headers have been received for a stream.
   virtual void OnStreamHeaders(QuicStreamId stream_id,
@@ -175,7 +176,8 @@ class NET_EXPORT_PRIVATE QuicSession : public QuicConnectionVisitorInterface {
   QuicPacketCreator::Options* options() { return connection()->options(); }
 
   // Returns the number of currently open streams, including those which have
-  // been implicitly created.
+  // been implicitly created, but excluding the reserved headers and crypto
+  // streams.
   virtual size_t GetNumOpenStreams() const;
 
   void MarkWriteBlocked(QuicStreamId id, QuicPriority priority);