There are basically two parts to the hack. One is to figure out the files changed, in the devtools, and update them on the localhost. Second part is to refresh the browser, whenever the localhost files change.
For first part, we hack into devtools, to figure out the files, and upload them to a nodejs app, which based on the path provided, and the current directory, updates the files. The path and files to be included are available in patch-devtools directory. The server is in devsync.coffee
For second part, we use socket.io library, in nodejs, to talk with the chrome devtools via websockets. This is again implemented in devsync.coffee.
The last part is installation.chromiumer.sh fetchs a chromium and devtools build, and patches it and puts it in ~/.devsync on the first run of devsync command.
I know, pretty ugly hack :)
If you wana play with the muck, you would have to download the chromium and devtools and patch devtools with files in the patch-devtools directory. Rest of the code is in devtools.coffee, in the root directory of the project. Let ciju know if you need more details.