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

chrome/test/webdriver/commands/execute_async_script_command.cc

Index: chrome/test/webdriver/commands/execute_async_script_command.cc
diff --git a/chrome/test/webdriver/commands/execute_async_script_command.cc b/chrome/test/webdriver/commands/execute_async_script_command.cc
index 8acd4b87412668e29f9dd5e14e20e830aaa957ca..60cd56c8bfab7ce8e867cdde2b0fe1f9dc4eaa7e 100644
--- a/chrome/test/webdriver/commands/execute_async_script_command.cc
+++ b/chrome/test/webdriver/commands/execute_async_script_command.cc
@@ -13,7 +13,7 @@ namespace webdriver {
 
 ExecuteAsyncScriptCommand::ExecuteAsyncScriptCommand(
     const std::vector<std::string>& path_segments,
-    const DictionaryValue* const parameters)
+    DictionaryValue* const parameters)
     : WebDriverCommand(path_segments, parameters) {}
 
 ExecuteAsyncScriptCommand::~ExecuteAsyncScriptCommand() {}
@@ -30,7 +30,7 @@ void ExecuteAsyncScriptCommand::ExecutePost(Response* const response) {
     return;
   }
 
-  ListValue* args;
+  const ListValue* args;
   if (!GetListParameter("args", &args)) {
     response->SetError(new Error(
         kBadRequest, "No script arguments specified"));