Clean up VMState a little bit.

src/builtins.cc

Index: src/builtins.cc
diff --git a/src/builtins.cc b/src/builtins.cc
index 30edf579e62234fdd162af7a8ea99c6fb580f0ee..fe2592deb8bbc7e43bf7adef0e34a47f59e8ea03 100644
--- a/src/builtins.cc
+++ b/src/builtins.cc
@@ -1321,7 +1321,7 @@ MUST_USE_RESULT static MaybeObject* HandleApiCallHelper(
     v8::Handle<v8::Value> value;
     {
       // Leaving JavaScript.
-      VMState state(isolate, EXTERNAL);
+      VMState<EXTERNAL> state(isolate);
       ExternalCallbackScope call_scope(isolate,
                                        v8::ToCData<Address>(callback_obj));
       value = callback(new_args);
@@ -1398,7 +1398,7 @@ MUST_USE_RESULT static MaybeObject* HandleApiCallAsFunctionOrConstructor(
     v8::Handle<v8::Value> value;
     {
       // Leaving JavaScript.
-      VMState state(isolate, EXTERNAL);
+      VMState<EXTERNAL> state(isolate);
       ExternalCallbackScope call_scope(isolate,
                                        v8::ToCData<Address>(callback_obj));
       value = callback(new_args);