Deprecate FLAGS_quic_disable_pre_30. Remove QUIC versions [25-29].

net/quic/quic_framer.h

Index: net/quic/quic_framer.h
diff --git a/net/quic/quic_framer.h b/net/quic/quic_framer.h
index 383b3fd6d5c1a20442cde5b4ddd91b0ed0b2062b..067083a794592b092202f4e99829ed1ea20e24c0 100644
--- a/net/quic/quic_framer.h
+++ b/net/quic/quic_framer.h
@@ -233,9 +233,6 @@ class NET_EXPORT_PRIVATE QuicFramer {
   static size_t GetStopWaitingFrameSize(
       QuicVersion version,
       QuicPacketNumberLength packet_number_length);
-  // Size in bytes of all reset stream frame without the error details.
-  // Used before QUIC_VERSION_25.
-  static size_t GetMinRstStreamFrameSize();
   // Size in bytes of all reset stream frame fields.
   static size_t GetRstStreamFrameSize();
   // Size in bytes of all connection close frame fields without the error