Summary:
We need to provide Yoga clients with means of detecting overflow in flexbox layout. This information can be used later to identify a non-overflowing layout variant among others.
Flexbox layout considered overflown if (this is *not* an exhaustive list):
- if any child node overflows
- [no-wrap] total flex basis of all child nodes is greater than available space in parent and there are no flexible children
- [no-wrap] after flexing there is still not enough space to layout all child nodes
Reviewed By: gkassabli
Differential Revision: D5336645
fbshipit-source-id: c4f87d1754d7bac848e8d347b31d619393b94d2c
