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

chrome/test/webdriver/commands/keys_command.cc

Index: chrome/test/webdriver/commands/keys_command.cc
diff --git a/chrome/test/webdriver/commands/keys_command.cc b/chrome/test/webdriver/commands/keys_command.cc
index 0e2b10e4fc16879485efc4ca1ac6f38df3a6db6a..962a886751f3887a387117c9370a829d5e8afd74 100644
--- a/chrome/test/webdriver/commands/keys_command.cc
+++ b/chrome/test/webdriver/commands/keys_command.cc
@@ -13,7 +13,7 @@
 namespace webdriver {
 
 KeysCommand::KeysCommand(const std::vector<std::string>& path_segments,
-                         const DictionaryValue* const parameters)
+                         DictionaryValue* const parameters)
     : WebDriverCommand(path_segments, parameters) {}
 
 KeysCommand::~KeysCommand() {}
@@ -23,7 +23,7 @@ bool KeysCommand::DoesPost() {
 }
 
 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"));