Javascript Blob.slice method cross-browser?

Doing a bit of learning about the Blob type with File access in HTML5 capable browsers and I discovered that Chrome doesn't use Blob.slice() but Blob.webkitSlice().

Does anyone know if there is a method for this that is accepted cross-browser yet or do I need to write my own?

If I need to write my own, can anyone guide me to where this method is defined in Firefox and IE9? (and probably Opera too)

EDIT

Found the Firefox definition and it a开发者_StackOverflow社区ppears that it used to use slice() but now uses mozSlice().

So that leaves Opera and IE9+

Epascarello answered it above in the comments:

File api is not supported in IE9, caniuse.com