HostResolver supports optional CNAME lookups.

net/base/host_resolver.h

 // Copyright (c) 2010 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_HOST_RESOLVER_H_
 #define NET_BASE_HOST_RESOLVER_H_
 
 #include <string>
 
 #include "base/ref_counted.h"
@@ skipping 23 matching lines @@
 // goes out of scope).
 class HostResolver : public base::RefCountedThreadSafe<HostResolver> {
  public:
   // The parameters for doing a Resolve(). |hostname| and |port| are required,
   // the rest are optional (and have reasonable defaults).
   class RequestInfo {
    public:
     RequestInfo(const std::string& hostname, int port)
         : hostname_(hostname),
           address_family_(ADDRESS_FAMILY_UNSPECIFIED),
+          host_resolver_flags_(0),
           port_(port),
           allow_cached_response_(true),
           is_speculative_(false),
           priority_(MEDIUM) {}
 
     int port() const { return port_; }
     void set_port(int port) {
       port_ = port;
     }
 
     const std::string& hostname() const { return hostname_; }
     void set_hostname(const std::string& hostname) {
       hostname_ = hostname;
     }
 
     AddressFamily address_family() const { return address_family_; }
     void set_address_family(AddressFamily address_family) {
       address_family_ = address_family;
     }
 
+    HostResolverFlags host_resolver_flags() const {
+      return host_resolver_flags_;
+    }
+    void set_host_resolver_flags(HostResolverFlags host_resolver_flags) {
+      host_resolver_flags_ = host_resolver_flags;
+    }
+
     bool allow_cached_response() const { return allow_cached_response_; }
     void set_allow_cached_response(bool b) { allow_cached_response_ = b; }
 
     bool is_speculative() const { return is_speculative_; }
     void set_is_speculative(bool b) { is_speculative_ = b; }
 
     RequestPriority priority() const { return priority_; }
     void set_priority(RequestPriority priority) { priority_ = priority; }
 
     const GURL& referrer() const { return referrer_; }
     void set_referrer(const GURL& referrer) { referrer_ = referrer; }
 
    private:
     // The hostname to resolve.
     std::string hostname_;
 
     // The address family to restrict results to.
     AddressFamily address_family_;
 
+    // Flags for the address.
+    HostResolverFlags host_resolver_flags_;
+
     // The port number to set in the result's sockaddrs.
     int port_;
 
     // Whether it is ok to return a result from the host cache.
     bool allow_cached_response_;
 
     // Whether this request was started by the DNS prefetcher.
     bool is_speculative_;
 
     // The priority for the request.
@@ skipping 133 matching lines @@
 // (Except if a unit-test has changed the global HostResolverProc using
 // ScopedHostResolverProc to intercept requests to the system).
 // |network_change_notifier| must outlive HostResolver.  It can optionally be
 // NULL, in which case HostResolver will not respond to network changes.
 HostResolver* CreateSystemHostResolver(
     NetworkChangeNotifier* network_change_notifier);
 
 }  // namespace net
 
 #endif  // NET_BASE_HOST_RESOLVER_H_