Bug 491464 will append '-shark' to the build target in update queries, eg Darwin_x86_64-gcc3-u-i386-x86_64-shark, if --enable-shark is given at configure time. We _may_ want blocklist to do the same for ADU purposes, and/or to keep both in sync. However, the xpcshell test harness for the add-on manager doesn't get preprocessed at the moment, so it's not possible to make build time changes based on MOZ_SHARK being defined (which is what I'm doing for updates). Mossop expressed an interest in moving to preprocessing but that's beyond the scope of what I want to do in Bug 491464. Or perhaps there may be a clever way to test for shark support at run-time. Please fix/wontfix as appropriate.

I wonder if that info should be added to nsIXULAppInfo. Presumably annotating DTrace builds could be useful in the future too - so a more generic solution would be nice.

Per policy at https://wiki.mozilla.org/Bug_Triage/Projects/Bug_Handling/Bug_Husbandry#Inactive_Bugs. If this bug is not an enhancement request or a bug not present in a supported release of Firefox, then it may be reopened.