Clean up VMState a little bit.

src/handles.cc

Index: src/handles.cc
diff --git a/src/handles.cc b/src/handles.cc
index 059ff2486db28c62c318ff0ab04000e0f2900b7f..5a5773ebd0f231544d646a40d7ba1ebdc606460a 100644
--- a/src/handles.cc
+++ b/src/handles.cc
@@ -565,7 +565,7 @@ v8::Handle<v8::Array> GetKeysForNamedInterceptor(Handle<JSReceiver> receiver,
     LOG(isolate, ApiObjectAccess("interceptor-named-enum", *object));
     {
       // Leaving JavaScript.
-      VMState state(isolate, EXTERNAL);
+      VMState<EXTERNAL> state(isolate);
       result = enum_fun(info);
     }
   }
@@ -590,7 +590,7 @@ v8::Handle<v8::Array> GetKeysForIndexedInterceptor(Handle<JSReceiver> receiver,
     LOG(isolate, ApiObjectAccess("interceptor-indexed-enum", *object));
     {
       // Leaving JavaScript.
-      VMState state(isolate, EXTERNAL);
+      VMState<EXTERNAL> state(isolate);
       result = enum_fun(info);
 #if ENABLE_EXTRA_CHECKS
       CHECK(result.IsEmpty() || v8::Utils::OpenHandle(*result)->IsJSObject());