Related discussion:
- https://bugzilla.mozilla.org/show_bug.cgi?id=1652925
It's not clear the code here will fix the reported
issue, but I did identify that the subframe
dictionary of a very long-lived web page can
theoretically grow unbound.
These spurious error messages can occur when a
extension framework API method return a
rejected Promise. In uBO the results of
browserAction methods is not used so it can be
safely discarded.
Related feedback:
- https://www.reddit.com/r/uBlockOrigin/comments/d6zbqv/
For static filter `popup` filter purpose, the URL of the
embedded frame from which the popup was launched will
be used in the matching algorithm.
