I read that early builds of Chrome supported ActiveX, but was later restricted to certain MIME types (for support for say Windows Media Player). I then read Google was goin
I'm not an expert but it sounds to me that this is something you could only do if you built the browser yourself - ie, not something done in a web page. I'm not sure that the sources for Chrome are publicly available (I think they are though), but the sources are what you'd probably need to change for this.