Summary:
Main change is to the property diffing - we now use the last known props set on the view rather than the default props to compute the diff. This requires exposing a `getProps` method on all view components which should be fine I think.
I also realized that in more complex animations with multiple nodes, the node that the animation starts on might not be connected to a view, so we don't know if it's fabric just based on that, so we have to do a recursive search through the children to find if there are any that are associated with a fabric view to decide we should start the animation immediately. Unfortunately there can still be a timing gap here since the animated API is async and the uimanager API is sync - I'll need to change the animated API to be sync to completely fix this.
Reviewed By: shergin
Differential Revision: D14732028
fbshipit-source-id: 882c056b0b63aa576f8e42439be405cf7fb3147a