Add feature flags for scheduler experiments (#22105)

Author: rickhanlonii

packages/scheduler/src/SchedulerFeatureFlags.js

@@ -9,3 +9,6 @@
 export const enableSchedulerDebugging = false;
 export const enableIsInputPending = false;
 export const enableProfiling = false;
+export const enableIsInputPendingContinuous = false;
+export const frameYieldMs = 5;
+export const continuousYieldMs = 50;

packages/scheduler/src/forks/Scheduler.js

@@ -11,6 +11,10 @@
 import {
   enableSchedulerDebugging,
   enableProfiling,
+  enableIsInputPending,
+  enableIsInputPendingContinuous,
+  frameYieldMs,
+  continuousYieldMs,
 } from '../SchedulerFeatureFlags';
 
 import {push, pop, peek} from '../SchedulerMinHeap';
@@ -36,8 +40,6 @@ import {
   startLoggingProfilingEvents,
 } from '../SchedulerProfiling';
 
-import {enableIsInputPending} from '../SchedulerFeatureFlags';
-
 let getCurrentTime;
 const hasPerformanceNow =
   typeof performance === 'object' && typeof performance.now === 'function';
@@ -98,7 +100,7 @@ const isInputPending =
     ? navigator.scheduling.isInputPending.bind(navigator.scheduling)
     : null;
 
-const continuousOptions = {includeContinuous: true};
+const continuousOptions = {includeContinuous: enableIsInputPendingContinuous};
 
 function advanceTimers(currentTime) {
   // Check for tasks that are no longer delayed and add them to the queue.
@@ -427,9 +429,8 @@ let taskTimeoutID = -1;
 // thread, like user events. By default, it yields multiple times per frame.
 // It does not attempt to align with frame boundaries, since most tasks don't
 // need to be frame aligned; for those that do, use requestAnimationFrame.
-// TODO: Make these configurable
-let frameInterval = 5;
-const continuousInputInterval = 50;
+let frameInterval = frameYieldMs;
+const continuousInputInterval = continuousYieldMs;
 const maxInterval = 300;
 let startTime = -1;
 
@@ -506,7 +507,7 @@ function forceFrameRate(fps) {
     frameInterval = Math.floor(1000 / fps);
   } else {
     // reset the framerate
-    frameInterval = 5;
+    frameInterval = frameYieldMs;
   }
 }
 

packages/scheduler/src/forks/SchedulerFeatureFlags.www-dynamic.js

@@ -15,3 +15,6 @@
 export const enableIsInputPending = __VARIANT__;
 export const enableSchedulerDebugging = __VARIANT__;
 export const enableProfiling = __VARIANT__;
+export const enableIsInputPendingContinuous = __VARIANT__;
+export const frameYieldMs = 5;
+export const continuousYieldMs = 50;

packages/scheduler/src/forks/SchedulerFeatureFlags.www.js

@@ -13,6 +13,9 @@ export const {
   enableIsInputPending,
   enableSchedulerDebugging,
   enableProfiling: enableProfilingFeatureFlag,
+  enableIsInputPendingContinuous,
+  frameYieldMs,
+  continuousYieldMs,
 } = dynamicFeatureFlags;
 
 export const enableProfiling = __PROFILE__ && enableProfilingFeatureFlag;