Revert "www: remove dynamic feature flag enableSchedulingProfiler" (#29995)

Reverts #29994

Author: kassens

packages/shared/forks/ReactFeatureFlags.www-dynamic.js

@@ -40,6 +40,8 @@ export const disableLegacyMode = __VARIANT__;
 // NOTE: This feature will only work in DEV mode; all callsites are wrapped with __DEV__.
 export const enableDebugTracing = __EXPERIMENTAL__;
 
+export const enableSchedulingProfiler = __VARIANT__;
+
 export const enableInfiniteRenderLoopDetection = __VARIANT__;
 
 // TODO: These flags are hard-coded to the default values used in open source.

packages/shared/forks/ReactFeatureFlags.www.js

@@ -59,7 +59,9 @@ export const enableAsyncActions = true;
 export const disableInputAttributeSyncing = false;
 export const enableLegacyFBSupport = true;
 
-export const enableSchedulingProfiler = __DEV__;
+// Logs additional User Timing API marks for use with an experimental profiling tool.
+export const enableSchedulingProfiler: boolean =
+  __PROFILE__ && dynamicFeatureFlags.enableSchedulingProfiler;
 
 export const disableLegacyContext = __EXPERIMENTAL__;
 export const enableGetInspectorDataForInstanceInProduction = false;