annotate: always prepare ancestry context of base fctx (issue4600) This patch extends the workaround introduced by dd01834a696f. Even if the base fctx is the same as intorrev, _ancestrycontext must be built for faster _changeid lookup. repo: https://hg.mozilla.org/releases/mozilla-beta command: hg annotate -r 4954faa47dd0 gfx/thebes/gfxWindowsPlatform.cpp before: 52.450 sec after: 1.820 sec