Added support for multiple parameters to Extension API callbacks.

chrome/browser/extensions/extension_preference_api.cc

 // 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.
 
 #include "chrome/browser/extensions/extension_preference_api.h"
 
 #include <map>
 #include <utility>
 
 #include "base/memory/singleton.h"
@@ skipping 349 matching lines @@
   result->Set(keys::kValue,
               transformer->BrowserToExtensionPref(pref->GetValue()));
 
   // Retrieve incognito status.
   if (incognito) {
     ExtensionPrefs* ep = profile_->GetExtensionService()->extension_prefs();
     result->SetBoolean(keys::kIncognitoSpecific,
                        ep->HasIncognitoPrefValue(browser_pref));
   }
 
-  result_.reset(result.release());
+  SetSingleResult(result.release());
   return true;
 }
 
 SetPreferenceFunction::~SetPreferenceFunction() { }
 
 bool SetPreferenceFunction::RunImpl() {
   std::string pref_key;
   EXTENSION_FUNCTION_VALIDATE(args_->GetString(0, &pref_key));
   DictionaryValue* details = NULL;
   EXTENSION_FUNCTION_VALIDATE(args_->GetDictionary(1, &details));
@@ skipping 97 matching lines @@
   }
 
   std::string browser_pref;
   if (!ValidateBrowserPref(pref_key, &browser_pref))
     return false;
 
   ExtensionPrefs* prefs = profile_->GetExtensionService()->extension_prefs();
   prefs->RemoveExtensionControlledPref(extension_id(), browser_pref, scope);
   return true;
 }