Revert "Add back "default address family" to HostResolver"

net/dns/host_resolver.h

Index: net/dns/host_resolver.h
diff --git a/net/dns/host_resolver.h b/net/dns/host_resolver.h
index ba5078705d4ff78ff1a6bc590c79524f1cb32c57..f909e7b004e332d253efd1692db65b7d6a3daf91 100644
--- a/net/dns/host_resolver.h
+++ b/net/dns/host_resolver.h
@@ -213,14 +213,6 @@ class NET_EXPORT HostResolver {
       const PersistCallback& persist_callback,
       std::unique_ptr<const base::Value> old_data);
 
-  // Sets the default AddressFamily to use when requests have left it
-  // unspecified. For example, this could be used to restrict resolution
-  // results to AF_INET by passing in ADDRESS_FAMILY_IPV4, or to
-  // AF_INET6 by passing in ADDRESS_FAMILY_IPV6. See http://crbug.com/696569 for
-  // why this option is necessary.
-  virtual void SetDefaultAddressFamily(AddressFamily address_family);
-  virtual AddressFamily GetDefaultAddressFamily() const;
-
   // Sets the HostResolver to assume that IPv6 is unreachable when on a wifi
   // connection. See https://crbug.com/696569 for further context.
   virtual void SetNoIPv6OnWifi(bool no_ipv6_on_wifi);