A top-level array (i.e., if a policy directly requires an array) won't be affected by this problem, because if the array is missing, that means that that policy is not present, so it will be ignored.
However, this can affect an array that is expected inside another object, for more complex policy types (like the popups permission which accepts both an 'allow' and a 'block' array of URLs.
In the future, we should implement the 'required' property as defined by the JSON-Schema standard, but there's not a strong use case for it yet, so let's do the simple solution for now
MozReview-Commit-ID: 4MTBTsPYlX8
This patch was autogenerated by my decomponents.py
It covers almost every file with the extension js, jsm, html, py,
xhtml, or xul.
It removes blank lines after removed lines, when the removed lines are
preceded by either blank lines or the start of a new block. The "start
of a new block" is defined fairly hackily: either the line starts with
//, ends with */, ends with {, <
