base: Add Is* functions to Value class.

net/base/transport_security_state.cc

Index: net/base/transport_security_state.cc
diff --git a/net/base/transport_security_state.cc b/net/base/transport_security_state.cc
index e82734d73a096145904f39e983b8cabae9ae8d8d..4570f5a1eca86541242995f1412f30f240956865 100644
--- a/net/base/transport_security_state.cc
+++ b/net/base/transport_security_state.cc
@@ -372,7 +372,7 @@ bool TransportSecurityState::Deserialise(
     std::map<std::string, DomainState>* out) {
   scoped_ptr<Value> value(
       base::JSONReader::Read(input, false /* do not allow trailing commas */));
-  if (!value.get() || !value->IsType(Value::TYPE_DICTIONARY))
+  if (!value.get() || !value->IsDictionary())
     return false;
 
   DictionaryValue* dict_value = reinterpret_cast<DictionaryValue*>(value.get());