In bug 1047523, froydnj pointed out that mHistogramMap doesn't outlive the string keys it uses, so it can use nsDepCharHashKey. On OSX desktop, on a newly-opened browser, this saves 38kb of memory. I'm not sure how telemetry works on B2G, but if it is there, it might be worth backporting some places, as it is super simple.
Created attachment 8466534 [details] [diff] [review] TelemetryImpl::mHistogramMap can use nsDepCharHashKey.
3 years ago