Temporary fix for grabbing wrong rAF polyfill in ReactScheduler (face…

…book#12837)

* Temporary fix for grabbing wrong rAF polyfill in ReactScheduler

**what is the change?:**
For now...
We need to grab a slightly different implementation of rAF internally at
FB than in Open Source. Making rAF a dependency of the ReactScheduler
module allows us to fork the dependency at FB.

NOTE: After this lands we have an alternative plan to make this module
separate from React and require it before our Facebook timer polyfills
are applied. But want to land this now to keep master in a working state
and fix bugs folks are seeing at Facebook.

Thanks @sebmarkbage @acdlite and @sophiebits for discussing the options
and trade-offs for solving this issue.

**why make this change?:**
This fixes a problem we're running into when experimenting with
ReactScheduler internally at Facebook, **and* it's part of our long term
plan to use dependency injection with the scheduler to make it easier to
test and adjust.

**test plan:**
Ran tests, lint, flow, and will manually test when syncing into
Facebook's codebase.

**issue:**
See internal task T29442940

* ran prettier

packages/react-scheduler/src/ReactScheduler.js

@@ -39,20 +39,7 @@ type CallbackConfigType = {|
 |};
 
 import ExecutionEnvironment from 'fbjs/lib/ExecutionEnvironment';
-import warning from 'fbjs/lib/warning';
-
-if (__DEV__) {
-  if (
-    ExecutionEnvironment.canUseDOM &&
-    typeof requestAnimationFrame !== 'function'
-  ) {
-    warning(
-      false,
-      'React depends on requestAnimationFrame. Make sure that you load a ' +
-        'polyfill in older browsers. https://fb.me/react-polyfills',
-    );
-  }
-}
+import requestAnimationFrameForReact from 'shared/requestAnimationFrameForReact';
 
 const hasNativePerformanceNow =
   typeof performance === 'object' && typeof performance.now === 'function';
@@ -232,7 +219,7 @@ if (!ExecutionEnvironment.canUseDOM) {
       if (!isAnimationFrameScheduled) {
         // Schedule another animation callback so we retry later.
         isAnimationFrameScheduled = true;
-        requestAnimationFrame(animationTick);
+        requestAnimationFrameForReact(animationTick);
       }
     }
   };
@@ -298,7 +285,7 @@ if (!ExecutionEnvironment.canUseDOM) {
       // might want to still have setTimeout trigger scheduleWork as a backup to ensure
       // that we keep performing work.
       isAnimationFrameScheduled = true;
-      requestAnimationFrame(animationTick);
+      requestAnimationFrameForReact(animationTick);
     }
     return newCallbackId;
   };

packages/shared/forks/requestAnimationFrameForReact.www.js

@@ -0,0 +1,10 @@
+/**
+ * Copyright (c) 2013-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+'use strict';
+
+export default require('requestAnimationFrameForReact');

packages/shared/requestAnimationFrameForReact.js

@@ -0,0 +1,28 @@
+/**
+ * Copyright (c) 2013-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow
+ */
+
+'use strict';
+
+import ExecutionEnvironment from 'fbjs/lib/ExecutionEnvironment';
+import warning from 'fbjs/lib/warning';
+
+if (__DEV__) {
+  if (
+    ExecutionEnvironment.canUseDOM &&
+    typeof requestAnimationFrame !== 'function'
+  ) {
+    warning(
+      false,
+      'React depends on requestAnimationFrame. Make sure that you load a ' +
+        'polyfill in older browsers. https://fb.me/react-polyfills',
+    );
+  }
+}
+
+export default requestAnimationFrame;

scripts/rollup/forks.js

@@ -74,6 +74,17 @@ const forks = Object.freeze({
     return null;
   },
 
+  // This logic is forked on www to use the 'acrossTransitions' version.
+  'shared/requestAnimationFrameForReact': (bundleType, entry) => {
+    switch (bundleType) {
+      case FB_WWW_DEV:
+      case FB_WWW_PROD:
+        return 'shared/forks/requestAnimationFrameForReact.www.js';
+      default:
+        return null;
+    }
+  },
+
   // This logic is forked on www to blacklist warnings.
   'shared/lowPriorityWarning': (bundleType, entry) => {
     switch (bundleType) {