Fixed performance regression in `ShadowView`s layout process
Fixed performance regression in `ShadowView`s layout process

Summary:
This fixes perf regression which was introduced by recent refactoring of the layout process.
That is how it used to be:
https://github.com/facebook/react-native/blob/114c258045ccca3a4433de206c7983b42d14c03b/React/Views/RCTShadowView.m#L160-L166
Note: We have to resert this flag in indication that we already applied those changes and we don't need to traverse this subtree until it is changed again.

Reviewed By: fkgozali

Differential Revision: D7343564

fbshipit-source-id: ba7e00bc5fe4992d777eed20ba0d959fd8f6c037

exponent/react-native,janicduplessis/react-native,pandiaraj44/react-native,javache/react-native,exponentjs/react-native,exponent/react-native,myntra/react-native,arthuralee/react-native,arthuralee/react-native,hoangpham95/react-native,facebook/react-native,javache/react-native,myntra/react-native,pandiaraj44/react-native,facebook/react-native,facebook/react-native,myntra/react-native,arthuralee/react-native,janicduplessis/react-native,javache/react-native,arthuralee/react-native,hoangpham95/react-native,javache/react-native,hammerandchisel/react-native,myntra/react-native,exponentjs/react-native,myntra/react-native,hammerandchisel/react-native,janicduplessis/react-native,facebook/react-native,exponent/react-native,javache/react-native,javache/react-native,hammerandchisel/react-native,hammerandchisel/react-native,javache/react-native,exponentjs/react-native,janicduplessis/react-native,myntra/react-native,pandiaraj44/react-native,hammerandchisel/react-native,exponentjs/react-native,facebook/react-native,pandiaraj44/react-native,hammerandchisel/react-native,exponent/react-native,facebook/react-native,exponentjs/react-native,myntra/react-native,hammerandchisel/react-native,pandiaraj44/react-native,myntra/react-native,janicduplessis/react-native,hoangpham95/react-native,hoangpham95/react-native,hammerandchisel/react-native,arthuralee/react-native,pandiaraj44/react-native,exponent/react-native,exponent/react-native,hoangpham95/react-native,hoangpham95/react-native,exponentjs/react-native,facebook/react-native,janicduplessis/react-native,facebook/react-native,javache/react-native,exponentjs/react-native,myntra/react-native,hoangpham95/react-native,pandiaraj44/react-native,exponent/react-native,pandiaraj44/react-native,exponentjs/react-native,janicduplessis/react-native,javache/react-native,hoangpham95/react-native,exponent/react-native,facebook/react-native,janicduplessis/react-native