Would it be possible to add CORS header to the HTTP access to git repos?
This would allow browser based apps using JS git clients to be able to push/pull using smart-http protocol. The only workaround currently is to deploy webapps as Chrome Apps (eg. Tailor, Git-Browser) or FirefoxOS Apps which gives the ability to white-list domains allowed to x-domain access.
This would also depend on https://bitbucket.org/site/master/issue/6666/detect-git-requests-by-content-type-header being fixed first of course.