RenderingDiagnostics.FrameProfEnabled is the master toggle for the
upcoming permanent frame profiler (ACDREAM_FRAME_PROF=1, runtime
mirror via DebugVM.FrameProf). GpuFrameTimer wraps a depth-4 ring of
TimeElapsed queries for whole-frame GPU time, mirroring
WbDrawDispatcher's query idiom (including the #125 never-begun-slot
guard). Caller must not run this while ACDREAM_WB_DIAG=1 owns
TimeElapsed queries — GL forbids nested TimeElapsed queries.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
