Summary:
@public
This is quite a big diff but the actual meaningful change is simple: now we use ShadowView class instead of ShadowNode in mutation instructions.
Note:
* In some places (especially during diffing) we have to operate with ShadowNodeViewPair objects (which represents a pair of ShadowNode and ShadowView). The reason for that is that we cannot construct child ShadowViews from parent ShadowViews because they don't have any information about children.
* `ShadowTree::emitLayoutEvents` is now much simpler because ShadowView better represents the specifics of this kind of object.
* The code in RCTMountingManager also became simpler.
This change will allow us to implement more cool tricks soon.
Reviewed By: mdvacca
Differential Revision: D9403564
fbshipit-source-id: dbc7c61af250144d6c7335a01dc30df0005559a2
0792fba63f