Pass reason for measure pass along with measurecallbackend event (#566)

Summary:
Pull Request resolved: https://github.com/facebook/litho/pull/566

Pull Request resolved: https://github.com/facebook/react-native/pull/25702

Pass reason for each measure callback to the flipper plugin

Reviewed By: davidaurelio

Differential Revision: D16221771

fbshipit-source-id: 2e72e1ebb3c7e633d189e7a7a81d655ac9531e51

yoga/event/event.cpp

@@ -12,6 +12,27 @@
 namespace facebook {
 namespace yoga {
 
+const char* LayoutPassToString(const LayoutPassReason value) {
+  switch (value) {
+    case kInitial:
+      return "initial";
+    case kMeasureChild:
+      return "measure";
+    case kAbsMeasureChild:
+      return "abs_measure";
+    case kFlex:
+      return "flex";
+    case kAbsLayout:
+      return "abs_layout";
+    case kStretch:
+      return "stretch";
+    case kMultilineStretch:
+      return "multiline_stretch";
+    default:
+      return "unknown";
+  }
+}
+
 namespace {
 
 struct Node {

yoga/event/event.h

@@ -32,6 +32,18 @@ struct LayoutData {
   int measureCallbacks;
 };
 
+enum LayoutPassReason : int {
+  kInitial = 0,
+  kMeasureChild = 1,
+  kAbsMeasureChild = 2,
+  kFlex = 3,
+  kAbsLayout = 4,
+  kStretch = 5,
+  kMultilineStretch = 6
+};
+
+const char* LayoutPassToString(const LayoutPassReason value);
+
 struct Event {
   enum Type {
     NodeAllocation,
@@ -114,6 +126,7 @@ struct Event::TypedData<Event::MeasureCallbackEnd> {
   YGMeasureMode heightMeasureMode;
   float measuredWidth;
   float measuredHeight;
+  const LayoutPassReason reason;
 };
 
 template <>