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

chrome/test/webdriver/commands/command.cc

Index: chrome/test/webdriver/commands/command.cc
diff --git a/chrome/test/webdriver/commands/command.cc b/chrome/test/webdriver/commands/command.cc
index 7f4686de4e34f7317c67a26dd9d6aa3c36ce87f6..0144f70de3b09c6bba769509fa17fe690799c027 100644
--- a/chrome/test/webdriver/commands/command.cc
+++ b/chrome/test/webdriver/commands/command.cc
@@ -7,7 +7,7 @@
 namespace webdriver {
 
 Command::Command(const std::vector<std::string>& path_segments,
-                 const DictionaryValue* const parameters)
+                 DictionaryValue* const parameters)
     : path_segments_(path_segments),
       parameters_(parameters) {}
 
@@ -40,7 +40,7 @@ bool Command::HasParameter(const std::string& key) const {
 }
 
 bool Command::IsNullParameter(const std::string& key) const {
-  Value* value;
+  const Value* value;
   return parameters_.get() &&
          parameters_->Get(key, &value) &&
          value->IsType(Value::TYPE_NULL);
@@ -81,7 +81,7 @@ bool Command::GetDictionaryParameter(const std::string& key,
 }
 
 bool Command::GetListParameter(const std::string& key,
-                               ListValue** out) const {
+                               const ListValue** out) const {
   return parameters_.get() != NULL && parameters_->GetList(key, out);
 }