Set correct initial value for AnimatedComponent for styles backed by …

…native animated nodes

Summary:
In AnimatedComponent.render, we get the initial values of any styles backed by AnimatedNode, but ONLY for non-native animations. Thus, if convert an animated node to native before the call to render to mount the component, we will end up not applying the initial value until after the component is mounted. This may result in a visible flicker as the expected value is applied some time after the component is mounted and visible.
- Without native driver: BaseViewManager.setTransform called during view preallocation (ViewManager.createViewInstance)
- With native driver: BaseViewManager.setTransform called during MountingManager.updateProps (called from PropsAnimatedNode.updateView)

This diff removes the isNative check in AnimatedStyle and AnimatedProps when traversing style props. This shouldn't be a problem:
- Created as non-native, animated with JS driver
  - This diff does not affect this scenario
- Created as non-native, animated with native driver
  - Initial value is applied correctly on render/mount. On subsequent renders, the outdated value from JS side will not apply on the platform view as it has not changed.
- Created as native, animated with native driver
  - Initial value is applied correctly on render/mount. On subsequent renders, the outdated value from JS side will not apply on the platform view as it has not changed.

Changelog:
[Internal][Fixed] - Set correct initial value for AnimatedComponent for styles backed by native animated nodes

Reviewed By: JoshuaGross, javache

Differential Revision: D36612758

fbshipit-source-id: 922d6534c605b3eb0a1d9476753111b726f138f2

Libraries/Animated/nodes/AnimatedProps.js

@@ -41,11 +41,7 @@ class AnimatedProps extends AnimatedNode {
     for (const key in this._props) {
       const value = this._props[key];
       if (value instanceof AnimatedNode) {
-        if (!value.__isNative || value instanceof AnimatedStyle) {
-          // We cannot use value of natively driven nodes this way as the value we have access from
-          // JS may not be up to date.
-          props[key] = value.__getValue();
-        }
+        props[key] = value.__getValue();
       } else if (value instanceof AnimatedEvent) {
         props[key] = value.__getHandler();
       } else {

Libraries/Animated/nodes/AnimatedStyle.js

@@ -39,11 +39,7 @@ class AnimatedStyle extends AnimatedWithChildren {
     for (const key in style) {
       const value = style[key];
       if (value instanceof AnimatedNode) {
-        if (!value.__isNative) {
-          // We cannot use value of natively driven nodes this way as the value we have access from
-          // JS may not be up to date.
-          updatedStyle[key] = value.__getValue();
-        }
+        updatedStyle[key] = value.__getValue();
       } else if (value && !Array.isArray(value) && typeof value === 'object') {
         // Support animating nested values (for example: shadowOffset.height)
         updatedStyle[key] = this._walkStyleAndGetValues(value);