[algorithms] Save button not working on master

Hello, I'm getting the following JS error when pressing the "Save" button after forking an algorithm. The button seems to work on the staging system, but not on my local checkout of the master HEAD.

How to reproduce it:

1. Fork an algorithm
2. Set a name
3. Click on the save button

The save button has no effect. Looking at the error console, I get the following:

My version of Safari (on OS X 10.10.4):