I improved a couple of things in the code to get JavaScript garbage collector statistics via WebKit SPI: 1) I changed the code to use HashCountedSet instead of CFSet at the low levels. 2) I updated the SPI and internal method names to better reflect how the collector works these days (but old SPI is left for compatibility)
Created attachment 6253 [details] make JS statistics code portable
Comment on attachment 6253 [details] make JS statistics code portable javaScriptRootObjecTypeCounts is missing a "t" Otherwise, r=me.
Maciej landed this earlier (with the typo!).