The default configuration of the tool detects goog.Disposable objects which were not dispose()d. goog.EventTarget is a subclass of goog.Disposable, and if an EventTarget is not disposed, event listeners are not discarded properly, and event listeners in turn keep DOM objects alive. It's possible to configure the tool to detect other similar misuses.
You can find more details about this project here.
This is a conversation on Google product forum. Google engineers really don't know what is VBA? Or they just refuse to acknowledge the existence of VBA? The full conversation can be found at https://productforums.google.com/forum/m/#!topic/chrome/zY-8vP1lIys