[ResourceTiming] resourcetimingbufferfull doesn't have access to the rejected entry

Hello.
As a note, I would have hoped that the resourcetimingbufferfull event would
have had, as part of the event, access to the new performance entry that
"is being dropped on the floor" so that it can be processed etc.

As it is today, if people listen for that event, they are basically
guaranteed to lose at least one Entry before they clear them all or raise
the buffer size, etc.
Cheers!