Make sure ExternalCallbackScope is always created when VM state changes to EXTERNAL

src/builtins.cc

Index: src/builtins.cc
diff --git a/src/builtins.cc b/src/builtins.cc
index fd7dd8a60dd7b304424063ea81a2cd1353ef3f75..c72ba1f9000371dd2c764b7678b11d2c94abef43 100644
--- a/src/builtins.cc
+++ b/src/builtins.cc
@@ -1267,14 +1267,7 @@ MUST_USE_RESULT static MaybeObject* HandleApiCallHelper(
                                      args.length() - 1,
                                      is_construct);
 
-    v8::Handle<v8::Value> value;
-    {
-      // Leaving JavaScript.
-      VMState<EXTERNAL> state(isolate);
-      ExternalCallbackScope call_scope(isolate,
-                                       v8::ToCData<Address>(callback_obj));
-      value = custom.Call(callback);
-    }
+    v8::Handle<v8::Value> value = custom.Call(callback);
     if (value.IsEmpty()) {
       result = heap->undefined_value();
     } else {
@@ -1343,14 +1336,7 @@ MUST_USE_RESULT static MaybeObject* HandleApiCallAsFunctionOrConstructor(
                                      &args[0] - 1,
                                      args.length() - 1,
                                      is_construct_call);
-    v8::Handle<v8::Value> value;
-    {
-      // Leaving JavaScript.
-      VMState<EXTERNAL> state(isolate);
-      ExternalCallbackScope call_scope(isolate,
-                                       v8::ToCData<Address>(callback_obj));
-      value = custom.Call(callback);
-    }
+    v8::Handle<v8::Value> value = custom.Call(callback);
     if (value.IsEmpty()) {
       result = heap->undefined_value();
     } else {