Fixed image tinting

Summary:
public

A previous refactor introduced a bug where setting the tintColor of an <Image> to null no longer cleared the tint. This fixes it again.

Reviewed By: javache

Differential Revision: D2744279

fb-gh-sync-id: 1b5e0d546bf456d7b93e2ceee73c568c185c305c

Libraries/Image/RCTImageView.m

@@ -108,12 +108,6 @@ RCT_NOT_IMPLEMENTED(- (instancetype)init)
   }
 }
 
-- (void)setTintColor:(UIColor *)tintColor
-{
-  super.tintColor = tintColor;
-  self.renderingMode = tintColor ? UIImageRenderingModeAlwaysTemplate : UIImageRenderingModeAlwaysOriginal;
-}
-
 - (void)setRenderingMode:(UIImageRenderingMode)renderingMode
 {
   if (_renderingMode != renderingMode) {

Libraries/Image/RCTImageViewManager.m

@@ -33,6 +33,13 @@ RCT_EXPORT_VIEW_PROPERTY(onLoad, RCTDirectEventBlock)
 RCT_EXPORT_VIEW_PROPERTY(onLoadEnd, RCTDirectEventBlock)
 RCT_REMAP_VIEW_PROPERTY(resizeMode, contentMode, UIViewContentMode)
 RCT_EXPORT_VIEW_PROPERTY(source, RCTImageSource)
-RCT_EXPORT_VIEW_PROPERTY(tintColor, UIColor)
+RCT_CUSTOM_VIEW_PROPERTY(tintColor, UIColor, RCTImageView)
+{
+  // Default tintColor isn't nil - it's inherited from the superView - but we
+  // want to treat a null json value for `tintColor` as meaning 'disable tint',
+  // so we toggle `renderingMode` here instead of in `-[RCTImageView setTintColor:]`
+  view.tintColor = [RCTConvert UIColor:json] ?: defaultView.tintColor;
+  view.renderingMode = json ? UIImageRenderingModeAlwaysTemplate : defaultView.renderingMode;
+}
 
 @end