API: Remove explicit profiling

API: Remove explicit profiling

The profileIn/profileOut pair should be covered by the Xhprof profiling
of the method calls it was wrapping.

The profileDBIn/profileDBOut pair are covered by profiling done by the
Database class.

Nothing in extensions in Gerrit is calling anything besides the
profileIn/profileOut pair (and likely those are only to avoid core
formerly throwing exceptions from internal profileDBIn/profileDBOut
calls), and nothing in core or extensions-in-Gerrit is using the methods
for fetching profiling data.

The methods are left as stubs for now to allow for backwards
compatibility in extensions.

Change-Id: I05ba4e2762dc86d5e2bafc183dce701239b43f5c