Cancel any outstanding host resolve when calling SOCKSClientSocket::Disconnec...

net/base/host_resolver.h

 // Copyright (c) 2006-2008 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 167 matching lines @@
   // called.
   ~SingleRequestHostResolver();
 
   // Resolves the given hostname (or IP address literal), filling out the
   // |addresses| object upon success. See HostResolver::Resolve() for details.
   int Resolve(const HostResolver::RequestInfo& info,
               AddressList* addresses,
               CompletionCallback* callback,
               LoadLog* load_log);
 
+  // Cancels the in-progress request, if any. This prevents the callback
+  // from being invoked. Resolve() can be called again after cancelling.
+  void Cancel();
+
  private:
   // Callback for when the request to |resolver_| completes, so we dispatch
   // to the user's callback.
   void OnResolveCompletion(int result);
 
   // The actual host resolver that will handle the request.
   scoped_refptr<HostResolver> resolver_;
 
   // The current request (if any).
   HostResolver::RequestHandle cur_request_;
   CompletionCallback* cur_request_callback_;
 
   // Completion callback for when request to |resolver_| completes.
   net::CompletionCallbackImpl<SingleRequestHostResolver> callback_;
 
   DISALLOW_COPY_AND_ASSIGN(SingleRequestHostResolver);
 };
 
 // Creates a HostResolver implementation that queries the underlying system.
 // (Except if a unit-test has changed the global HostResolverProc using
 // ScopedHostResolverProc to intercept requests to the system).
 HostResolver* CreateSystemHostResolver();
 
 }  // namespace net
 
 #endif  // NET_BASE_HOST_RESOLVER_H_