Google brought me to this question:
Is there a way to identify the busy (CPU-consuming) tab in Firefox?
But that question is marked as a duplicate of this one:
How to find out which firefox tab is using most CPU or memory?
The problem is that the second question already has an accepted answer, but that answer is now out of date (Firefox already does what the suggested extension offers, and the extension is no longer compatible, although alternatives are available). Incidentally the older question has far fewer upvotes and views than the closed question.
I am wondering if there could have been a better way to handle this.
Personally I feel the older question was a bit broad (asking about CPU and memory together). And I feel uncomfortable that the answer was accepted. There really is no single "right" answer to this question We will hopefully see more alternative solutions appearing in the coming years.
My suggestion would be to have kept the 2014 question open, but distinguish it from the older question by editing it to make it specifically about Firefox >30.
It seems odd that Google brings users to the closed question rather than the original. But I think Google is right: it has more useful information on it!
If you agree that these two questions look a bit messy now, do you think anything can be done to make up-to-date information easily available to users?
