Consistently suggest ephemeral port for QUIC client

net/quic/quic_stream_factory.h

Index: net/quic/quic_stream_factory.h
diff --git a/net/quic/quic_stream_factory.h b/net/quic/quic_stream_factory.h
index 95a3d369d9069490a27d3666c2945c2e0c46a671..805d8e99bb1b342e8f3db7c45fe73a85e0ae3ccb 100644
--- a/net/quic/quic_stream_factory.h
+++ b/net/quic/quic_stream_factory.h
@@ -230,6 +230,14 @@ class NET_EXPORT_PRIVATE QuicStreamFactory
 
   base::WeakPtrFactory<QuicStreamFactory> weak_factory_;
 
+  // Each profile will (probably) have a unique port_entropy_ value.  This value
+  // is used to help seed a pseudo-random number generator (PortSuggester) so
+  // that we consistently (within this profile) suggest the same ephemeral port
+  // when we re-connect to any given server/port.  The differences between
+  // profiles (probablistically) prevent two profiles from colliding in their
+  // ephemeral port requests.
+  uint64 port_entropy_;
+
   DISALLOW_COPY_AND_ASSIGN(QuicStreamFactory);
 };