Make enableSchedulingProfiler flag dynamic (for PROFILING builds only)

Author: Brian Vaughn

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

@@ -25,6 +25,8 @@ export const decoupleUpdatePriorityFromScheduler = __VARIANT__;
 // NOTE: This feature will only work in DEV mode; all callsights are wrapped with __DEV__.
 export const enableDebugTracing = __EXPERIMENTAL__;
 
+export const enableSchedulingProfiler = __VARIANT__;
+
 // This only has an effect in the new reconciler. But also, the new reconciler
 // is only enabled when __VARIANT__ is true. So this is set to the opposite of
 // __VARIANT__ so that it's `false` when running against the new reconciler.

packages/shared/forks/ReactFeatureFlags.www.js

@@ -35,7 +35,8 @@ export const {
 
 export const enableProfilerTimer = __PROFILE__;
 export const enableProfilerCommitHooks = __PROFILE__;
-export const enableProfilerNestedUpdatePhase = __PROFILE__;
+export const enableProfilerNestedUpdatePhase =
+  __PROFILE__ && dynamicFeatureFlags.enableSchedulingProfiler;
 
 // Logs additional User Timing API marks for use with an experimental profiling tool.
 export const enableSchedulingProfiler = __PROFILE__;