Isolates generic DnsClient from AsyncHostResolver.

net/base/dns_util.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef NET_BASE_DNS_UTIL_H_
 #define NET_BASE_DNS_UTIL_H_
 #pragma once
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/string_piece.h"
 #include "net/base/net_export.h"
 
 namespace net {
 
 // DNSDomainFromDot - convert a domain string to DNS format. From DJB's
 // public domain DNS library.
 //
 //   dotted: a string in dotted form: "www.google.com"
 //   out: a result in DNS form: "\x03www\x06google\x03com\x00"
-NET_EXPORT_PRIVATE bool DNSDomainFromDot(const std::string& dotted,
+NET_EXPORT_PRIVATE bool DNSDomainFromDot(const base::StringPiece& dotted,
                                          std::string* out);
 
 // DNSDomainToString coverts a domain in DNS format to a dotted string.
-NET_EXPORT_PRIVATE std::string DNSDomainToString(const std::string& domain);
+NET_EXPORT_PRIVATE std::string DNSDomainToString(
+    const base::StringPiece& domain);
 
 // Returns true iff the given character is in the set of valid DNS label
 // characters as given in RFC 3490, 4.1, 3(a)
 NET_EXPORT_PRIVATE bool IsSTD3ASCIIValidCharacter(char c);
 
 // Returns the hostname by trimming the ending dot, if one exists.
-NET_EXPORT std::string TrimEndingDot(const std::string& host);
+NET_EXPORT std::string TrimEndingDot(const base::StringPiece& host);
+
+// TODO(szym): remove all definitions below once DnsRRResolver migrates to
+// DnsClient
 
 // DNS class types.
 static const uint16 kClassIN = 1;
 
 // DNS resource record types. See
 // http://www.iana.org/assignments/dns-parameters
 // WARNING: if you're adding any new values here you may need to add them to
 // dnsrr_resolver.cc:DnsRRIsParsedByWindows.
 static const uint16 kDNS_A = 1;
 static const uint16 kDNS_CNAME = 5;
@@ skipping 43 matching lines @@
   unsigned len_;
   const unsigned packet_len_;
 
   DISALLOW_COPY_AND_ASSIGN(DnsResponseBuffer);
 };
 
 
 }  // namespace net
 
 #endif  // NET_BASE_DNS_UTIL_H_