Add iOS support to ProxyService

chrome/browser/net/pref_proxy_config_tracker_impl.cc

 // 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.
 
 #include "chrome/browser/net/pref_proxy_config_tracker_impl.h"
 
 #include "base/bind.h"
 #include "base/values.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/browser/prefs/pref_set_observer.h"
@@ skipping 296 matching lines @@
     }
     if (update_pending_)
       OnProxyConfigChanged(config_state, new_config);
   } else {
     NOTREACHED() << "Unexpected notification of type " << type;
   }
 }
 
 ProxyPrefs::ConfigState PrefProxyConfigTrackerImpl::ReadPrefConfig(
     net::ProxyConfig* config) {
+#if defined(OS_IOS)
+  return ProxyPrefs::CONFIG_UNSET;

[wtc, 2012/08/30 18:52:01]

I suggest putting the rest of this function inside a #else
block.

I am surprised that the iOS compiler does not warn about
unreachable code after the return statement.

[eroman, 2012/08/31 20:02:43]

Why is this necessary?

+#endif
+
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   // Clear the configuration and source.
   *config = net::ProxyConfig();
   ProxyPrefs::ConfigState config_state = ProxyPrefs::CONFIG_UNSET;
 
   const PrefService::Preference* pref =
       pref_service_->FindPreference(prefs::kProxy);
   DCHECK(pref);
 
   const DictionaryValue* dict = pref_service_->GetDictionary(prefs::kProxy);
   DCHECK(dict);
   ProxyConfigDictionary proxy_dict(dict);
 
   if (PrefConfigToNetConfig(proxy_dict, config)) {
     if (!pref->IsUserModifiable() || pref->HasUserSetting()) {
       if (pref->IsManaged())
         config_state = ProxyPrefs::CONFIG_POLICY;
       else if (pref->IsExtensionControlled())
         config_state = ProxyPrefs::CONFIG_EXTENSION;
       else
         config_state = ProxyPrefs::CONFIG_OTHER_PRECEDE;
     } else  {
       config_state = ProxyPrefs::CONFIG_FALLBACK;
     }
   }
 
   return config_state;
 }