Delete ensureComponentIsNative.js

Summary:
This function was used by Touchable*. It was removed from the Touchables in D6494579 in 2017. The only remaining callsite was ImageBackground which is attaching a ref directly to the View so we know it is a native component.

This is needed for some setNativeProps cleanup

Reviewed By: sahrens

Differential Revision: D16796973

fbshipit-source-id: 19379094b3b91920efac4bf1969fc22d4b80bcc6

Libraries/Components/UnimplementedViews/UnimplementedView.js

@@ -17,12 +17,6 @@ const StyleSheet = require('../../StyleSheet/StyleSheet');
  * View component and renders its children.
  */
 class UnimplementedView extends React.Component<$FlowFixMeProps> {
-  setNativeProps() {
-    // Do nothing.
-    // This method is required in order to use this view as a Touchable* child.
-    // See ensureComponentIsNative.js for more info
-  }
-
   render(): React.Node {
     // Workaround require cycle from requireNativeComponent
     const View = require('../View/View');

Libraries/Image/ImageBackground.js

@@ -14,8 +14,6 @@ const React = require('react');
 const StyleSheet = require('../StyleSheet/StyleSheet');
 const View = require('../Components/View/View');
 
-const ensureComponentIsNative = require('../Components/Touchable/ensureComponentIsNative');
-
 /**
  * Very simple drop-in replacement for <Image> which supports nesting views.
  *
@@ -45,7 +43,6 @@ class ImageBackground extends React.Component<$FlowFixMeProps> {
     // Work-around flow
     const viewRef = this._viewRef;
     if (viewRef) {
-      ensureComponentIsNative(viewRef);
       viewRef.setNativeProps(props);
     }
   }

jest/setup.js

@@ -172,9 +172,6 @@ jest
 
     return ReactNative;
   })
-  .mock('../Libraries/Components/Touchable/ensureComponentIsNative', () => () =>
-    true,
-  )
   // Mock modules defined by the native layer (ex: Objective-C, Java)
   .mock('../Libraries/BatchedBridge/NativeModules', () => ({
     AlertManager: {