Implemented Profiler onCommit() and onPostCommit() hooks (facebook#17910)

* Implemented Profiler onCommit() and onPostCommit() hooks
* Added enableProfilerCommitHooks feature flag for commit hooks
* Moved onCommit and onPassiveCommit behind separate feature flag

Author: Brian Vaughn

packages/react-reconciler/src/ReactFiber.js

@@ -826,13 +826,8 @@ function createFiberFromProfiler(
   key: null | string,
 ): Fiber {
   if (__DEV__) {
-    if (
-      typeof pendingProps.id !== 'string' ||
-      typeof pendingProps.onRender !== 'function'
-    ) {
-      console.error(
-        'Profiler must specify an "id" string and "onRender" function as props',
-      );
+    if (typeof pendingProps.id !== 'string') {
+      console.error('Profiler must specify an "id" as a prop');
     }
   }
 
@@ -842,6 +837,13 @@ function createFiberFromProfiler(
   fiber.type = REACT_PROFILER_TYPE;
   fiber.expirationTime = expirationTime;
 
+  if (enableProfilerTimer) {
+    fiber.stateNode = {
+      effectDuration: 0,
+      passiveEffectDuration: 0,
+    };
+  }
+
   return fiber;
 }
 

packages/react-reconciler/src/ReactFiberBeginWork.js

@@ -580,6 +580,12 @@ function updateProfiler(
 ) {
   if (enableProfilerTimer) {
     workInProgress.effectTag |= Update;
+
+    // Reset effect durations for the next eventual effect phase.
+    // These are reset during render to allow the DevTools commit hook a chance to read them,
+    const stateNode = workInProgress.stateNode;
+    stateNode.effectDuration = 0;
+    stateNode.passiveEffectDuration = 0;
   }
   const nextProps = workInProgress.pendingProps;
   const nextChildren = nextProps.children;
@@ -2944,6 +2950,12 @@ function beginWork(
             if (hasChildWork) {
               workInProgress.effectTag |= Update;
             }
+
+            // Reset effect durations for the next eventual effect phase.
+            // These are reset during render to allow the DevTools commit hook a chance to read them,
+            const stateNode = workInProgress.stateNode;
+            stateNode.effectDuration = 0;
+            stateNode.passiveEffectDuration = 0;
           }
           break;
         case SuspenseComponent: {