Remove calls to ObjectData::o_getArray(arr, false).

Summary: The second argument already defaults to false.

While I'm here, make some Class* arguments into const Class*.

Reviewed By: @swtaarrs

Differential Revision: D1741711

Signature: t1:1741711:1418723072:aa3c21c17a5fa7617162cae9154a89b05dcaea23