Fix thread race when fetching the ProfilingInfo object.

Problem is:
1) Compiler fetches the ProfilingInfo of A, it's null.
2) Mutator creates the ProfilingInfo.
3) Compiler notifies it's not using A anymore, calls
   ProfilingInfo::DecrementInlineUse -> Crash as we expected
   ProfilingInfo::IncrementUse to be called before.

Also update some namings to better reflect what is going on.

Change-Id: I55ea4c5d81988131467095e18a0d13a8be9d0ef7