Fix crash on IP address change.

net/base/mapped_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_MAPPED_HOST_RESOLVER_H_
 #define NET_BASE_MAPPED_HOST_RESOLVER_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 14 matching lines @@
 
   // HostResolver methods:
   virtual int Resolve(const RequestInfo& info,
                       AddressList* addresses,
                       CompletionCallback* callback,
                       RequestHandle* out_req,
                       const BoundNetLog& net_log);
   virtual void CancelRequest(RequestHandle req);
   virtual void AddObserver(Observer* observer);
   virtual void RemoveObserver(Observer* observer);
-  virtual void Flush() { impl_->Flush(); }
   virtual HostResolverImpl* GetAsHostResolverImpl();
 
   // Adds a rule to this mapper. The format of the rule can be one of:
   //
   //   "MAP" <hostname_pattern> <replacement_host> [":" <replacement_port>]
   //   "EXCLUDE" <hostname_pattern>
   //
   // The <replacement_host> can be either a hostname, or an IP address literal.
   //
   // Returns true if the rule was successfully parsed and added.
@@ skipping 26 matching lines @@
 
   scoped_refptr<HostResolver> impl_;
 
   MapRuleList map_rules_;
   ExclusionRuleList exclusion_rules_;
 };
 
 }  // namespace net
 
 #endif  // NET_BASE_MAPPED_HOST_RESOLVER_H_