Allow ProxyConfigService to report "no configuration set"

net/proxy/proxy_config_service_mac.h

 // Copyright (c) 2011 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_CONFIG_SERVICE_MAC_H_
 #define NET_PROXY_PROXY_CONFIG_SERVICE_MAC_H_
 #pragma once
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "base/observer_list.h"
 #include "net/base/network_config_watcher_mac.h"
 #include "net/proxy/proxy_config.h"
 #include "net/proxy/proxy_config_service.h"
 
 namespace net {
 
 class ProxyConfigServiceMac : public ProxyConfigService {
  public:
   // Constructs a ProxyConfigService that watches the Mac OS system settings.
   // This instance is expected to be operated and deleted on |io_loop|
   // (however it may be constructed from a different thread).
   explicit ProxyConfigServiceMac(MessageLoop* io_loop);
   virtual ~ProxyConfigServiceMac();
 
  public:
   // ProxyConfigService implementation:
   virtual void AddObserver(Observer* observer);
   virtual void RemoveObserver(Observer* observer);
-  virtual bool GetLatestProxyConfig(ProxyConfig* config);
+  virtual ConfigAvailability GetLatestProxyConfig(ProxyConfig* config);
 
  private:
   class Helper;
 
   // Forwarder just exists to keep the NetworkConfigWatcherMac API out of
   // ProxyConfigServiceMac's public API.
   class Forwarder : public NetworkConfigWatcherMac::Delegate {
    public:
     explicit Forwarder(ProxyConfigServiceMac* net_config_watcher)
         : net_config_watcher_(net_config_watcher) {}
@@ skipping 31 matching lines @@
 
   // The thread that we expect to be operated on.
   MessageLoop* io_loop_;
 
   DISALLOW_COPY_AND_ASSIGN(ProxyConfigServiceMac);
 };
 
 }  // namespace net
 
 #endif  // NET_PROXY_PROXY_CONFIG_SERVICE_MAC_H_