Automattic/jetpack — pull request #246 by enkrates (2014-02-22 19:12:22+00:00)
Title: Enabling HTTPS for the Tumblr sharing button

The Tumblr image can be served over https, so this change
uses the http() method to use https when the page uses https.

I think this would work for a few other services in this module, but
I am just doing Tumblr to make sure I have the mechanics of a pull request
right.