HostResolver supports optional CNAME lookups.

net/base/mock_host_resolver.cc

 // 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.
 
 #include "net/base/mock_host_resolver.h"
 
 #include "base/string_util.h"
 #include "base/platform_thread.h"
 #include "base/ref_counted.h"
 #include "googleurl/src/url_canon_ip.h"
@@ skipping 131 matching lines @@
     AddressFamily address_family,
     const std::string& replacement) {
   DCHECK(!replacement.empty());
   Rule rule(Rule::kResolverTypeSystem, host_pattern,
             address_family, replacement, 0);
   rules_.push_back(rule);
 }
 
 void RuleBasedHostResolverProc::AddIPv6Rule(const std::string& host_pattern,
                                             const std::string& ipv6_literal) {
-  Rule rule(Rule::kResolverTypeIPV6Literal, host_pattern,
-            ADDRESS_FAMILY_UNSPECIFIED, ipv6_literal, 0);
+  Rule rule(Rule::kResolverTypeIPV6Literal,
+            host_pattern,
+            ADDRESS_FAMILY_UNSPECIFIED,
+            ipv6_literal,
+            0);
   rules_.push_back(rule);
 }
 
 void RuleBasedHostResolverProc::AddRuleWithLatency(
     const std::string& host_pattern,
     const std::string& replacement,
     int latency_ms) {
   DCHECK(!replacement.empty());
   Rule rule(Rule::kResolverTypeSystem, host_pattern,
             ADDRESS_FAMILY_UNSPECIFIED, replacement, latency_ms);
   rules_.push_back(rule);
 }
 
 void RuleBasedHostResolverProc::AllowDirectLookup(
     const std::string& host_pattern) {
   Rule rule(Rule::kResolverTypeSystem, host_pattern,
             ADDRESS_FAMILY_UNSPECIFIED, "", 0);
   rules_.push_back(rule);
 }
 
 void RuleBasedHostResolverProc::AddSimulatedFailure(
     const std::string& host_pattern) {
   Rule rule(Rule::kResolverTypeFail, host_pattern,
             ADDRESS_FAMILY_UNSPECIFIED, "", 0);
   rules_.push_back(rule);
 }
 
 int RuleBasedHostResolverProc::Resolve(const std::string& host,
                                        AddressFamily address_family,
+                                       HostResolverFlags host_resolver_flags,
                                        AddressList* addrlist) {
   RuleList::iterator r;
   for (r = rules_.begin(); r != rules_.end(); ++r) {
     bool matches_address_family =
         r->address_family == ADDRESS_FAMILY_UNSPECIFIED ||
         r->address_family == address_family;
 
     if (matches_address_family && MatchPatternASCII(host, r->host_pattern)) {
       if (r->latency_ms != 0)
         PlatformThread::Sleep(r->latency_ms);
 
       // Remap to a new host.
       const std::string& effective_host =
           r->replacement.empty() ? host : r->replacement;
 
       // Apply the resolving function to the remapped hostname.
       switch (r->resolver_type) {
         case Rule::kResolverTypeFail:
           return ERR_NAME_NOT_RESOLVED;
         case Rule::kResolverTypeSystem:
           return SystemHostResolverProc(effective_host,
                                         address_family,
+                                        host_resolver_flags,
                                         addrlist);
         case Rule::kResolverTypeIPV6Literal:
           return ResolveIPV6LiteralUsingGURL(effective_host, addrlist);
         default:
           NOTREACHED();
           return ERR_UNEXPECTED;
       }
     }
   }
-  return ResolveUsingPrevious(host, address_family, addrlist);
+  return ResolveUsingPrevious(host, address_family,
+                              host_resolver_flags, addrlist);
 }
 
 //-----------------------------------------------------------------------------
 
 ScopedDefaultHostResolverProc::ScopedDefaultHostResolverProc(
     HostResolverProc* proc) {
   Init(proc);
 }
 
 ScopedDefaultHostResolverProc::~ScopedDefaultHostResolverProc() {
   HostResolverProc* old_proc = HostResolverProc::SetDefault(previous_proc_);
   // The lifetimes of multiple instances must be nested.
   CHECK_EQ(old_proc, current_proc_);
 }
 
 void ScopedDefaultHostResolverProc::Init(HostResolverProc* proc) {
   current_proc_ = proc;
   previous_proc_ = HostResolverProc::SetDefault(current_proc_);
   current_proc_->SetLastProc(previous_proc_);
 }
 
 }  // namespace net