src: enable StreamPipe for generic StreamBases

PR-URL: nodejs#150
Reviewed-By: James M Snell <jasnell@gmail.com>

src/stream_pipe.cc

@@ -69,8 +69,6 @@ void StreamPipe::Unpipe(bool is_in_deletion) {
   if (pending_writes_ == 0)
     sink()->RemoveStreamListener(&writable_listener_);
 
-  if (is_in_deletion) return;
-
   // Delay the JS-facing part with SetImmediate, because this might be from
   // inside the garbage collector, so we can’t run JS here.
   HandleScope handle_scope(env()->isolate());
@@ -176,9 +174,7 @@ void StreamPipe::WritableListener::OnStreamAfterWrite(WriteWrap* w,
   }
 
   if (pipe->is_eof_) {
-    HandleScope handle_scope(pipe->env()->isolate());
-    InternalCallbackScope callback_scope(pipe,
-        InternalCallbackScope::kSkipTaskQueues);
+    AsyncScope async_scope(pipe);
     pipe->sink()->Shutdown();
     pipe->Unpipe();
     return;