Don't preresolve DNS if a fixed proxy configuration is in place.

net/proxy/proxy_service.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_PROXY_PROXY_SERVICE_H_
 #define NET_PROXY_PROXY_SERVICE_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 104 matching lines @@
   // the caller will not need to cancel the request.
   //
   // We use the three possible proxy access types in the following order,
   // doing fallback if one doesn't work.  See "pac_script_decider.h"
   // for the specifics.
   //   1.  WPAD auto-detection
   //   2.  PAC URL
   //   3.  named proxy
   //
   // Profiling information for the request is saved to |net_log| if non-NULL.
-  int ResolveProxy(const GURL& url,
-                   int load_flags,
-                   ProxyInfo* results,
-                   const net::CompletionCallback& callback,
-                   PacRequest** pac_request,
-                   NetworkDelegate* network_delegate,
-                   const BoundNetLog& net_log);
+  // This method is virtual for unit testing.

[eroman, 2014/09/23 20:50:42]

Can your tests can instead use: ProxyService::CreateFixed() ?

I don't want this to have to be virtual just for a test purpose.

[bemasc, 2014/09/24 18:34:37]

Done.

+  virtual int ResolveProxy(const GURL& url,
+                           int load_flags,
+                           ProxyInfo* results,
+                           const net::CompletionCallback& callback,
+                           PacRequest** pac_request,
+                           NetworkDelegate* network_delegate,
+                           const BoundNetLog& net_log);
 
   // This method is called after a failure to connect or resolve a host name.
   // It gives the proxy service an opportunity to reconsider the proxy to use.
   // The |results| parameter contains the results returned by an earlier call
   // to ResolveProxy.  The |net_error| parameter contains the network error
   // code associated with the failure. See "net/base/net_error_list.h" for a
   // list of possible values. The semantics of this call are otherwise
   // similar to ResolveProxy.
   //
   // NULL can be passed for |pac_request| if the caller will not need to
@@ skipping 286 matching lines @@
 
   // Whether child ProxyScriptDeciders should use QuickCheck
   bool quick_check_enabled_;
 
   DISALLOW_COPY_AND_ASSIGN(ProxyService);
 };
 
 }  // namespace net
 
 #endif  // NET_PROXY_PROXY_SERVICE_H_