In my personal experience, it is impossible to modify the browser behavior in Chrome, if the addon api does not allow for it - in firefox this is much easier to change as much of the interface logic is written in Javascript, and there are api's for just about anything.
Chrome does support the NPAPI api, however this is written in C++, and the documentation is (best) maintained by Mozilla.
Basically:
Your other option is to checkout the source code of Chrome, and attempt to understand it, modify it, and (possibly) get your changes committed back into the tree.
You might be able to get away with just this https://developers.google.com/chrome-developer-tools/docs/contributing
However, again, you are creating a debug version of Chrome.
In summary, there are no easy answers.