Loading a page while profiler is recording appears to crash the browser. I encountered this with the nightly build of r40023 and again with the nightly build of r40080. Steps to repeat: 1) Start WebKit. 2) Enable profiler (Command-Option-I, click Profiles, click Enable Profiling) 3) Begin recording (Click record) 4) Enter a URL (Command-L, type, return) 5) Crash.
Created attachment 26884 [details] Crash report
Confirmed with r40102, but I cannot get this to crash in a debug build.
*** This bug has been marked as a duplicate of 23551 ***