UserAgent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.162 Safari/537.36

Steps to reproduce the problem:
1. use chrome.runtime.connect to connect background js
2. 
3. 

What is the expected behavior?

What went wrong?
Here is my code: 
port = chrome.runtime.connect(extensionId, { 'name': token_ });
due to Chrome's develop document, the extensionId is optional, so I set: extensionId="", and then I got the error:
TypeError: Error in invocation of runtime.connect(optional string extensionId, optional object connectInfo): Invalid extension id: ''

Did this work before? Yes Release edition (65.xxx) and Beta edition (66.xxxx)

Chrome version: 67.0.3371.0  Channel: dev
OS Version: 10.13.3
Flash Version: