[m52] Send QUIC ping packets when there are draining streams, even if there are no open streams.

net/quic/quic_chromium_client_session.cc

Index: net/quic/quic_chromium_client_session.cc
diff --git a/net/quic/quic_chromium_client_session.cc b/net/quic/quic_chromium_client_session.cc
index 91f763c9d6dcdf6b4186589fe9adbb173342e40d..25f7224f2cafaf6e68ae62f6b757db5615850a60 100644
--- a/net/quic/quic_chromium_client_session.cc
+++ b/net/quic/quic_chromium_client_session.cc
@@ -914,6 +914,11 @@ void QuicChromiumClientSession::OnPathDegrading() {
   }
 }
 
+bool QuicChromiumClientSession::HasOpenDynamicStreams() const {
+  return QuicSession::HasOpenDynamicStreams() ||
+         GetNumDrainingOutgoingStreams() > 0;
+}
+
 void QuicChromiumClientSession::OnProofValid(
     const QuicCryptoClientConfig::CachedState& cached) {
   DCHECK(cached.proof_valid());