Add support to QUIC for QUIC_VERSION_8: for RSA-PSS signatures, set

net/quic/quic_protocol.cc

Index: net/quic/quic_protocol.cc
===================================================================
--- net/quic/quic_protocol.cc	(revision 216255)
+++ net/quic/quic_protocol.cc	(working copy)
@@ -129,6 +129,8 @@
       return MakeQuicTag('Q', '0', '0', '6');
     case QUIC_VERSION_7:
       return MakeQuicTag('Q', '0', '0', '7');
+    case QUIC_VERSION_8:
+      return MakeQuicTag('Q', '0', '0', '8');
     default:
       // This shold be an ERROR because we should never attempt to convert an
       // invalid QuicVersion to be written to the wire.
@@ -140,11 +142,14 @@
 QuicVersion QuicTagToQuicVersion(const QuicTag version_tag) {
   const QuicTag quic_tag_v6 = MakeQuicTag('Q', '0', '0', '6');
   const QuicTag quic_tag_v7 = MakeQuicTag('Q', '0', '0', '7');
+  const QuicTag quic_tag_v8 = MakeQuicTag('Q', '0', '0', '8');
 
   if (version_tag == quic_tag_v6) {
     return QUIC_VERSION_6;
   } else if (version_tag == quic_tag_v7) {
     return QUIC_VERSION_7;
+  } else if (version_tag == quic_tag_v8) {
+    return QUIC_VERSION_8;
   } else {
     // Reading from the client so this should not be considered an ERROR.
     DLOG(INFO) << "Unsupported QuicTag version: "
@@ -153,14 +158,15 @@
   }
 }
 
+#define RETURN_STRING_LITERAL(x) \
+case x: \
+return #x
+
 string QuicVersionToString(const QuicVersion version) {
-  // TODO(rjshade): Possibly start using RETURN_STRING_LITERAL here when we
-  //                start supporting a lot of versions.
   switch (version) {
-    case QUIC_VERSION_6:
-      return "QUIC_VERSION_6";
-    case QUIC_VERSION_7:
-      return "QUIC_VERSION_7";
+    RETURN_STRING_LITERAL(QUIC_VERSION_6);
+    RETURN_STRING_LITERAL(QUIC_VERSION_7);
+    RETURN_STRING_LITERAL(QUIC_VERSION_8);
     default:
       return "QUIC_VERSION_UNSUPPORTED";
   }