emberjs/data — pull request #1536 by lukemelia (2013-12-02 03:50:44+00:00)
Title: Allow `recordIsLoaded` to be called with a string for the type.

`recordIsLoaded` did not support execution with a string as the `type`
argument, only a DS.Model class reference. This commit makes either
form possible. Consistent with `find`, the `type` argument is
passed through `modelFor` to resolve a class reference.