Fabric: Removed unused code from ShadowTree
Fabric: Removed unused code from ShadowTree

Summary:
This is dead code.

Changelog: [Internal] Fabric-specific internal change.

Reviewed By: JoshuaGross

Differential Revision: D23681510

fbshipit-source-id: d2d1f7f97921401308badc417479d11588556ef8

myntra/react-native,pandiaraj44/react-native,janicduplessis/react-native,janicduplessis/react-native,myntra/react-native,facebook/react-native,facebook/react-native,myntra/react-native,pandiaraj44/react-native,facebook/react-native,janicduplessis/react-native,javache/react-native,arthuralee/react-native,pandiaraj44/react-native,facebook/react-native,facebook/react-native,javache/react-native,pandiaraj44/react-native,arthuralee/react-native,javache/react-native,javache/react-native,janicduplessis/react-native,pandiaraj44/react-native,pandiaraj44/react-native,janicduplessis/react-native,javache/react-native,myntra/react-native,janicduplessis/react-native,javache/react-native,javache/react-native,facebook/react-native,facebook/react-native,arthuralee/react-native,janicduplessis/react-native,arthuralee/react-native,myntra/react-native,myntra/react-native,janicduplessis/react-native,myntra/react-native,facebook/react-native,myntra/react-native,pandiaraj44/react-native,javache/react-native,myntra/react-native,javache/react-native,facebook/react-native,arthuralee/react-native,pandiaraj44/react-native