Correct const accessors in base/values.(h|cc)

chrome/browser/extensions/api/context_menu/context_menu_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/api/context_menu/context_menu_api.h"
 
 #include <string>
 
 #include "base/values.h"
 #include "base/string_number_conversions.h"
@@ skipping 41 matching lines @@
 }
 
 }  // namespace
 
 namespace extensions {
 
 bool ExtensionContextMenuFunction::ParseContexts(
     const DictionaryValue& properties,
     const char* key,
     MenuItem::ContextList* result) {
-  ListValue* list = NULL;
+  const ListValue* list = NULL;
   if (!properties.GetList(key, &list)) {
     return true;
   }
   MenuItem::ContextList tmp_result;
 
   std::string value;
   for (size_t i = 0; i < list->GetSize(); i++) {
     if (!list->GetString(i, &value))
       return false;
 
@@ skipping 77 matching lines @@
   return (value->GetAsInteger(&result->uid) ||
           value->GetAsString(&result->string_uid));
 }
 
 bool ExtensionContextMenuFunction::GetParent(const DictionaryValue& properties,
                                              const MenuManager& manager,
                                              MenuItem** result) {
   if (!properties.HasKey(kParentIdKey))
     return true;
   MenuItem::Id parent_id(profile()->IsOffTheRecord(), extension_id());
-  Value* parent_id_value = NULL;
+  const Value* parent_id_value = NULL;
   if (properties.Get(kParentIdKey, &parent_id_value) &&
       !ParseID(parent_id_value, &parent_id))
     return false;
 
   MenuItem* parent = manager.GetItemById(parent_id);
   if (!parent) {
     error_ = ExtensionErrorUtils::FormatErrorMessage(
         kCannotFindItemError, GetIDString(parent_id));
     return false;
   }
@@ skipping 197 matching lines @@
 
 bool RemoveAllContextMenusFunction::RunImpl() {
   ExtensionService* service = profile()->GetExtensionService();
   MenuManager* manager = service->menu_manager();
   manager->RemoveAllContextItems(GetExtension()->id());
   manager->WriteToStorage(GetExtension());
   return true;
 }
 
 }  // namespace extensions