LeakSanitizer detects some leaks in a mochitest-chrome run. It looks like what is leaking are AddrInfos, the mHostName fields of AddrInfo, NetAddrElement, and maybe something else. I'll attach the stacks that LSan reports, but I'm not sure which exact test is causing this.
I tried to narrow down which subdirectory is triggering this area by running it locally, but I didn't have any luck. My guess is there's some failure case somewhere that isn't handled properly.
Bug 1183781 should have fixed this.