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

chrome/test/webdriver/commands/keys_command.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/test/webdriver/commands/keys_command.h"
 
 #include "base/values.h"
 #include "chrome/test/webdriver/commands/response.h"
 #include "chrome/test/webdriver/webdriver_error.h"
 #include "chrome/test/webdriver/webdriver_session.h"
 #include "chrome/test/webdriver/webdriver_util.h"
 
 namespace webdriver {
 
 KeysCommand::KeysCommand(const std::vector<std::string>& path_segments,
                          const DictionaryValue* const parameters)
     : WebDriverCommand(path_segments, parameters) {}
 
 KeysCommand::~KeysCommand() {}
 
 bool KeysCommand::DoesPost() {
   return true;
 }
 
 void KeysCommand::ExecutePost(Response* const response) {
-  ListValue* key_list;
+  const ListValue* key_list;
   if (!GetListParameter("value", &key_list)) {
     response->SetError(new Error(
         kBadRequest, "Missing or invalid 'value' parameter"));
     return;
   }
 
   // Flatten the given array of strings into one.
   string16 keys;
   Error* error = FlattenStringArray(key_list, &keys);
   if (error) {
     response->SetError(error);
     return;
   }
 
   error = session_->SendKeys(keys);
   if (error) {
     response->SetError(error);
     return;
   }
 }
 
 }  // namespace webdriver