Created attachment 345254 [details]
a minimal example of a leaking issue

It seems that if I have a lambda function which only assigned a value to a global variable
and pass those lambda function to requestAnimationFrame the heap size growing all the time.
The growing of the heap depends on the size of the value that I want to assign. 

I am using "safari-technology-preview-34"

also If I pass an empty lambda function to "requestAnimationFrame" the "WeakSet::addAllocator" add a new block every time.