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

chrome/test/webdriver/commands/execute_command.cc

Index: chrome/test/webdriver/commands/execute_command.cc
diff --git a/chrome/test/webdriver/commands/execute_command.cc b/chrome/test/webdriver/commands/execute_command.cc
index 7bb5a9a72e22b7073e927240433b44fb42b56d6c..8f27d73800e71da8939972a53b3d68dd60434672 100644
--- a/chrome/test/webdriver/commands/execute_command.cc
+++ b/chrome/test/webdriver/commands/execute_command.cc
@@ -14,7 +14,7 @@
 namespace webdriver {
 
 ExecuteCommand::ExecuteCommand(const std::vector<std::string>& path_segments,
-                               const DictionaryValue* const parameters)
+                               DictionaryValue* const parameters)
     : WebDriverCommand(path_segments, parameters) {}
 
 ExecuteCommand::~ExecuteCommand() {}
@@ -30,7 +30,7 @@ void ExecuteCommand::ExecutePost(Response* const response) {
     return;
   }
 
-  ListValue* args;
+  const ListValue* args;
   if (!GetListParameter("args", &args)) {
     response->SetError(new Error(
         kBadRequest, "No script arguments specified"));