Disable (unstable) scheduler sampling profiler for OSS builds (facebook#20832)

* Disabled Scheduler sampling profiler for OSS builds
* Added missing conditional feature flag around profiling calls

Author: Brian Vaughn

packages/scheduler/src/Scheduler.js

@@ -181,12 +181,16 @@ function workLoop(hasTimeRemaining, initialTime) {
       currentTask.callback = null;
       currentPriorityLevel = currentTask.priorityLevel;
       const didUserCallbackTimeout = currentTask.expirationTime <= currentTime;
-      markTaskRun(currentTask, currentTime);
+      if (enableProfiling) {
+        markTaskRun(currentTask, currentTime);
+      }
       const continuationCallback = callback(didUserCallbackTimeout);
       currentTime = getCurrentTime();
       if (typeof continuationCallback === 'function') {
         currentTask.callback = continuationCallback;
-        markTaskYield(currentTask, currentTime);
+        if (enableProfiling) {
+          markTaskYield(currentTask, currentTime);
+        }
       } else {
         if (enableProfiling) {
           markTaskCompleted(currentTask, currentTime);

packages/scheduler/src/SchedulerFeatureFlags.js

@@ -8,4 +8,4 @@
 
 export const enableSchedulerDebugging = false;
 export const enableIsInputPending = false;
-export const enableProfiling = __PROFILE__;
+export const enableProfiling = false;

packages/scheduler/src/__tests__/SchedulerProfiling-test.js

@@ -44,7 +44,8 @@ function priorityLevelToString(priorityLevel) {
 }
 
 describe('Scheduler', () => {
-  if (!__PROFILE__) {
+  const {enableProfiling} = require('scheduler/src/SchedulerFeatureFlags');
+  if (!enableProfiling) {
     // The tests in this suite only apply when profiling is on
     it('profiling APIs are not available', () => {
       Scheduler = require('scheduler');