Created attachment 62680 [details]
A new fuzzer by lcamtuf described in bug 43040 produced the attached crash. We have no repro for now. Initial analysis of the attached info indicates a request for a large amount of memory leads to OOM and the code triggers a DebugBreak to terminate the renderer. If somebody can confirm this is what happened from the attached data, then this bug can probably be closed as "Won't Fix".
Otherwise, we'll have to find a repro or analyze possible code paths to find out what happened.
I suspect that it's possible with message ports to get a renderer to crash.
OOM => DebugBreak. News at 11.