Remove "Default Address Family" behavior from the HostResolver.

net/dns/host_resolver_impl.h

 // Copyright (c) 2012 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_DNS_HOST_RESOLVER_IMPL_H_
 #define NET_DNS_HOST_RESOLVER_IMPL_H_
 
 #include <map>
 
 #include "base/basictypes.h"
@@ skipping 117 matching lines @@
   int Resolve(const RequestInfo& info,
               RequestPriority priority,
               AddressList* addresses,
               const CompletionCallback& callback,
               RequestHandle* out_req,
               const BoundNetLog& source_net_log) override;
   int ResolveFromCache(const RequestInfo& info,
                        AddressList* addresses,
                        const BoundNetLog& source_net_log) override;
   void CancelRequest(RequestHandle req) override;
-  void SetDefaultAddressFamily(AddressFamily address_family) override;
-  AddressFamily GetDefaultAddressFamily() const override;
   void SetDnsClientEnabled(bool enabled) override;
   HostCache* GetHostCache() override;
   base::Value* GetDnsConfigAsValue() const override;
 
   void set_proc_params_for_test(const ProcTaskParams& proc_params) {
     proc_params_ = proc_params;
   }
 
+ protected:
+  // Probes IPv6 support and returns true if IPv6 support is enabled.
+  // Results are cached, i.e. when called repeatedly this method returns result
+  // from the first probe for some time before probing again.
+  virtual bool IsIPv6Reachable(const BoundNetLog& net_log);

[mmenke, 2015/06/03 13:31:03]

Drive-by nit:  This doesn't have to be protected for subclasses to override it.

[cbentzel, 2015/06/03 15:43:19]

Done.

+
  private:
   friend class HostResolverImplTest;
   class Job;
   class ProcTask;
   class LoopbackProbeJob;
   class DnsTask;
   class Request;
   typedef HostCache::Key Key;
   typedef std::map<Key, Job*> JobMap;
   typedef ScopedVector<Request> RequestsList;
@@ skipping 37 matching lines @@
   // Callback from HaveOnlyLoopbackAddresses probe.
   void SetHaveOnlyLoopbackAddresses(bool result);
 
   // Returns the (hostname, address_family) key to use for |info|, choosing an
   // "effective" address family by inheriting the resolver's default address
   // family when the request leaves it unspecified.
   Key GetEffectiveKeyForRequest(const RequestInfo& info,
                                 const IPAddressNumber* ip_number,
                                 const BoundNetLog& net_log);
 
-  // Probes IPv6 support and returns true if IPv6 support is enabled.
-  // Results are cached, i.e. when called repeatedly this method returns result
-  // from the first probe for some time before probing again.
-  bool IsIPv6Reachable(const BoundNetLog& net_log);
-
   // Records the result in cache if cache is present.
   void CacheResult(const Key& key,
                    const HostCache::Entry& entry,
                    base::TimeDelta ttl);
 
   // Removes |job| from |jobs_|, only if it exists.
   void RemoveJob(Job* job);
 
   // Aborts all in progress jobs with ERR_NETWORK_CHANGED and notifies their
   // requests. Might start new jobs.
@@ skipping 41 matching lines @@
   scoped_ptr<PrioritizedDispatcher> dispatcher_;
 
   // Limit on the maximum number of jobs queued in |dispatcher_|.
   size_t max_queued_jobs_;
 
   // Parameters for ProcTask.
   ProcTaskParams proc_params_;
 
   NetLog* net_log_;
 
-  // Address family to use when the request doesn't specify one.
-  AddressFamily default_address_family_;
-
   // If present, used by DnsTask and ServeFromHosts to resolve requests.
   scoped_ptr<DnsClient> dns_client_;
 
   // True if received valid config from |dns_config_service_|. Temporary, used
   // to measure performance of DnsConfigService: http://crbug.com/125599
   bool received_dns_config_;
 
   // Number of consecutive failures of DnsTask, counted when fallback succeeds.
   unsigned num_dns_failures_;
 
-  // True if probing is done for each Request to set address family. When false,
-  // explicit setting in |default_address_family_| is used.
-  bool probe_ipv6_support_;
-
   // True if DnsConfigService detected that system configuration depends on
   // local IPv6 connectivity. Disables probing.
   bool use_local_ipv6_;
 
   base::TimeTicks last_ipv6_probe_time_;
   bool last_ipv6_probe_result_;
 
   // True iff ProcTask has successfully resolved a hostname known to have IPv6
   // addresses using ADDRESS_FAMILY_UNSPECIFIED. Reset on IP address change.
   bool resolved_known_ipv6_hostname_;
 
   // Any resolver flags that should be added to a request by default.
   HostResolverFlags additional_resolver_flags_;
 
   // Allow fallback to ProcTask if DnsTask fails.
   bool fallback_to_proctask_;
 
   base::WeakPtrFactory<HostResolverImpl> weak_ptr_factory_;
 
   base::WeakPtrFactory<HostResolverImpl> probe_weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(HostResolverImpl);
 };
 
 }  // namespace net
 
 #endif  // NET_DNS_HOST_RESOLVER_IMPL_H_