Expose box sizing getters and setters in Yoga (#1701)

Summary:
Pull Request resolved: https://github.com/facebook/yoga/pull/1701

X-link: https://github.com/facebook/react-native/pull/46630

I would like to write some tests for box sizing that will drive a lot of my development as I implement content box. To do that, I need this publicly exposed. Obviously not that ideal since this currently does not do anything. Maybe we can name the value in such a way that its clear it is in development?

Changelog: [Internal]

Reviewed By: NickGerleman

Differential Revision: D63135970

fbshipit-source-id: 7520823bf925364eae45341531e012e80ec92284

javascript/src/Node.cpp

@@ -75,6 +75,10 @@ void Node::copyStyle(Node const& other) {
   YGNodeCopyStyle(m_node, other.m_node);
 }
 
+void Node::setBoxSizing(int boxSizing) {
+  YGNodeStyleSetBoxSizing(m_node, static_cast<YGBoxSizing>(boxSizing));
+}
+
 void Node::setPositionType(int positionType) {
   YGNodeStyleSetPositionType(m_node, static_cast<YGPositionType>(positionType));
 }
@@ -248,6 +252,10 @@ void Node::setGapPercent(int gutter, double gapLength) {
   YGNodeStyleSetGapPercent(m_node, static_cast<YGGutter>(gutter), gapLength);
 }
 
+int Node::getBoxSizing(void) const {
+  return YGNodeStyleGetBoxSizing(m_node);
+}
+
 int Node::getPositionType(void) const {
   return YGNodeStyleGetPositionType(m_node);
 }