Remove SPS profiler.

- Conditionals and code blocks. (MOZ_ENABLE_PROFILER_SPS)
- Stub out several profiler-only functions.

dom/workers/RuntimeService.cpp

@@ -2811,13 +2811,6 @@ WorkerThreadPrimaryRunnable::Run()
     }
 
     {
-#ifdef MOZ_ENABLE_PROFILER_SPS
-      PseudoStack* stack = mozilla_get_pseudo_stack();
-      if (stack) {
-        stack->sampleContext(cx);
-      }
-#endif
-
       {
         JSAutoRequest ar(cx);
 
@@ -2829,12 +2822,6 @@ WorkerThreadPrimaryRunnable::Run()
       }
 
       BackgroundChild::CloseForCurrentThread();
-
-#ifdef MOZ_ENABLE_PROFILER_SPS
-      if (stack) {
-        stack->sampleContext(nullptr);
-      }
-#endif
     }
 
     // There may still be runnables on the debugger event queue that hold a