Remove the last of the TLS fallback code.

net/ssl/ssl_config.h

Index: net/ssl/ssl_config.h
diff --git a/net/ssl/ssl_config.h b/net/ssl/ssl_config.h
index f48a86fcadac8bfeba5b4b7181aba8a8f83b3c5a..0cc7f55201bc060c0adaba85e973c1214aeffae2 100644
--- a/net/ssl/ssl_config.h
+++ b/net/ssl/ssl_config.h
@@ -41,9 +41,6 @@ NET_EXPORT extern const uint16_t kDefaultSSLVersionMin;
 // Default maximum protocol version.
 NET_EXPORT extern const uint16_t kDefaultSSLVersionMax;
 
-// Default minimum protocol version that it's acceptable to fallback to.
-NET_EXPORT extern const uint16_t kDefaultSSLVersionFallbackMin;
-
 // A collection of SSL-related configuration settings.
 struct NET_EXPORT SSLConfig {
   // Default to revocation checking.
@@ -88,12 +85,6 @@ struct NET_EXPORT SSLConfig {
   uint16_t version_min;
   uint16_t version_max;
 
-  // version_fallback_min contains the minimum version that is acceptable to
-  // fallback to. Versions before this may be tried to see whether they would
-  // have succeeded and thus to give a better message to the user, but the
-  // resulting connection won't be used in these cases.
-  uint16_t version_fallback_min;
-
   // Presorted list of cipher suites which should be explicitly prevented from
   // being used in addition to those disabled by the net built-in policy.
   //
@@ -155,10 +146,6 @@ struct NET_EXPORT SSLConfig {
 
   bool verify_ev_cert;  // True if we should verify the certificate for EV.
 
-  bool version_fallback;  // True if we are falling back to an older protocol
-                          // version (one still needs to decrement
-                          // version_max).
-
   // If cert_io_enabled is false, then certificate verification will not
   // result in additional HTTP requests. (For example: to fetch missing
   // intermediates or to perform OCSP/CRL fetches.) It also implies that online