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

net/quic/quic_session.cc

Index: net/quic/quic_session.cc
diff --git a/net/quic/quic_session.cc b/net/quic/quic_session.cc
index d6fae9b9f8f704094d1aeef850f8caba0ac1db19..7cc353a0e184d2a29ebdde2d1cc200a11f80b59c 100644
--- a/net/quic/quic_session.cc
+++ b/net/quic/quic_session.cc
@@ -86,6 +86,10 @@ class VisitorShim : public QuicConnectionVisitorInterface {
     return session_->HasPendingHandshake();
   }
 
+  virtual bool HasOpenDataStreams() const OVERRIDE {
+    return session_->HasOpenDataStreams();
+  }
+
  private:
   QuicSession* session_;
 };
@@ -301,6 +305,10 @@ bool QuicSession::HasPendingHandshake() const {
   return has_pending_handshake_;
 }
 
+bool QuicSession::HasOpenDataStreams() const {
+  return GetNumOpenStreams() > 0;
+}
+
 QuicConsumedData QuicSession::WritevData(
     QuicStreamId id,
     const IOVector& data,