Add a feature flag to disable Fabric layout animations

Summary:
tsia

Changelog: [Internal]

Reviewed By: rubennorte

Differential Revision: D34340023

fbshipit-source-id: 61956f1819f1f7e10dc2520c444fa5dd305d1363

Libraries/LayoutAnimation/LayoutAnimation.js

@@ -26,6 +26,12 @@ export type LayoutAnimationConfig = LayoutAnimationConfig_;
 type OnAnimationDidEndCallback = () => void;
 type OnAnimationDidFailCallback = () => void;
 
+let isLayoutAnimationEnabled: boolean = true;
+
+function setEnabled(value: boolean) {
+  isLayoutAnimationEnabled = value;
+}
+
 /**
  * Configures the next commit to be animated.
  *
@@ -43,6 +49,10 @@ function configureNext(
     return;
   }
 
+  if (!isLayoutAnimationEnabled) {
+    return;
+  }
+
   // Since LayoutAnimations may possibly be disabled for now on iOS (Fabric),
   // or Android (non-Fabric) we race a setTimeout with animation completion,
   // in case onComplete is never called
@@ -181,6 +191,7 @@ const LayoutAnimation = {
   spring: (configureNext.bind(null, Presets.spring): (
     onAnimationDidEnd?: OnAnimationDidEndCallback,
   ) => void),
+  setEnabled,
 };
 
 module.exports = LayoutAnimation;