Fabric: LayoutContext::affectedShadowNodes was removed

Summary:
Apparently, we don't need this functionality in Fabric because we compute mutation instactions during diffing anyways.
But we still need (will need) `LayoutContext` for sure.

Reviewed By: mdvacca

Differential Revision: D7857045

fbshipit-source-id: 4be2744d9abea473ead847f35f698104f94af33d

ReactCommon/fabric/core/layout/LayoutContext.h

@@ -24,12 +24,6 @@ struct LayoutContext {
    * Compound absolute position of the node relative to the root node.
    */
   Point absolutePosition {0, 0};
-
-  /*
-   * Collection of shadow nodes which were chanded during the layout pass,
-   * and which associated views might need to be updated.
-   */
-  std::shared_ptr<std::unordered_set<SharedLayoutableShadowNode>> affectedShadowNodes {nullptr};
 };
 
 } // namespace react

ReactCommon/fabric/uimanager/Scheduler.cpp

@@ -65,7 +65,6 @@ void Scheduler::uiManagerDidFinishTransaction(Tag rootTag, const SharedShadowNod
   auto nonConstNewRootShadowNode = std::const_pointer_cast<RootShadowNode>(newRootShadowNode);
 
   LayoutContext layoutContext = LayoutContext();
-  layoutContext.affectedShadowNodes = std::make_shared<std::unordered_set<SharedLayoutableShadowNode>>();
 
   LOG(INFO) << "Old Shadow Tree: \n" << oldRootShadowNode->getDebugDescription();
   LOG(INFO) << "New Shadow Tree *before* layout: \n" << newRootShadowNode->getDebugDescription();

ReactCommon/fabric/view/yoga/YogaLayoutableShadowNode.cpp

@@ -130,10 +130,7 @@ void YogaLayoutableShadowNode::layoutChildren(LayoutContext layoutContext) {
     auto nonConstYogaLayoutableChild = std::const_pointer_cast<YogaLayoutableShadowNode>(yogaLayoutableChild);
 
     LayoutMetrics childLayoutMetrics = layoutMetricsFromYogaNode(*nonConstYogaLayoutableChild->yogaNode_);
-    bool isAffected = nonConstYogaLayoutableChild->setLayoutMetrics(childLayoutMetrics);
-    if (isAffected) {
-      layoutContext.affectedShadowNodes->insert(child);
-    }
+    nonConstYogaLayoutableChild->setLayoutMetrics(childLayoutMetrics);
   }
 }