Memory-Stats.js: Minimal Monitor for JavaScript Heap Size via Performance.memory

Relevant bugs for Firefox:

implement performance.memory [0]

Need something like performance.memory, need to figure out what [1]

Please comment your use cases in these bugs.

[0] https://bugzilla.mozilla.org/show_bug.cgi?id=1124223

[1] https://bugzilla.mozilla.org/show_bug.cgi?id=1132852

I couldn't get this to work and some googling seems to suggest that --enable-precise-memory-info is no longer an option?