Revert QE for ReactFeatureFlags.reduceDeleteCreateMutation (#42339)

Summary:
Pull Request resolved: #42339

This diff cleans up the code added in D41900201 to run QE: https://fburl.com/qe2/ovgxlayy

More context: https://fb.workplace.com/groups/react.technologies.discussions/permalink/3479283292303384/

Changelog:
[Android][Internal] - Revert internal optimizations

Reviewed By: mdvacca

Differential Revision: D52750975

fbshipit-source-id: 675a3d0bb05094e35e47b35e6840fb2e5a24b9a1

packages/react-native/ReactAndroid/api/ReactAndroid.api

@@ -1911,7 +1911,6 @@ public class com/facebook/react/config/ReactFeatureFlags {
 	public static field enableViewRecycling Z
 	public static field excludeYogaFromRawProps Z
 	public static field fixStoppedSurfaceTagSetLeak Z
-	public static field reduceDeleteCreateMutation Z
 	public static field reduceDeleteCreateMutationLayoutAnimation Z
 	public static field rejectTurboModulePromiseOnNativeError Z
 	public static field traceTurboModulePromiseRejections Z

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/config/ReactFeatureFlags.java

@@ -112,12 +112,6 @@ public class ReactFeatureFlags {
    */
   public static boolean reduceDeleteCreateMutationLayoutAnimation = true;
 
-  /**
-   * Allow fix to drop delete...create mutations which could cause missing view state in Fabric
-   * SurfaceMountingManager.
-   */
-  public static boolean reduceDeleteCreateMutation = false;
-
   /** Report mount operations from the host platform to notify mount hooks. */
   public static boolean enableMountHooks = false;
 

packages/react-native/ReactAndroid/src/main/jni/react/fabric/FabricMountingManager.cpp

@@ -30,22 +30,10 @@
 
 namespace facebook::react {
 
-constexpr static auto kReactFeatureFlagsJavaDescriptor =
-    "com/facebook/react/config/ReactFeatureFlags";
-
-static bool getFeatureFlagValue(const char* name) {
-  static const auto reactFeatureFlagsClass =
-      jni::findClassStatic(kReactFeatureFlagsJavaDescriptor);
-  const auto field = reactFeatureFlagsClass->getStaticField<jboolean>(name);
-  return reactFeatureFlagsClass->getStaticFieldValue(field);
-}
-
 FabricMountingManager::FabricMountingManager(
     std::shared_ptr<const ReactNativeConfig>& config,
     jni::global_ref<JFabricUIManager::javaobject>& javaUIManager)
-    : javaUIManager_(javaUIManager),
-      reduceDeleteCreateMutation_(
-          getFeatureFlagValue("reduceDeleteCreateMutation")) {}
+    : javaUIManager_(javaUIManager) {}
 
 void FabricMountingManager::onSurfaceStart(SurfaceId surfaceId) {
   std::lock_guard lock(allocatedViewsMutex_);
@@ -288,30 +276,6 @@ void FabricMountingManager::executeMount(
         case ShadowViewMutation::Create: {
           bool shouldCreateView =
               !allocatedViewTags.contains(newChildShadowView.tag);
-          if (reduceDeleteCreateMutation_) {
-            // Detect DELETE...CREATE situation on the same node and do NOT push
-            // back to the mount items. This is an edge case that may happen
-            // when for example animation runs while commit happened, and we
-            // want to filter them out here to capture all possible sources of
-            // such mutations. The re-ordering logic here assumes no
-            // DELETE...CREATE in the mutations, as we will re-order mutations
-            // and batch all DELETE instructions in the end.
-            auto it = std::remove_if(
-                cppDeleteMountItems.begin(),
-                cppDeleteMountItems.end(),
-                [&](auto& deletedMountItem) -> bool {
-                  return deletedMountItem.oldChildShadowView.tag ==
-                      newChildShadowView.tag;
-                });
-            bool hasDeletedViewsWithSameTag = it != cppDeleteMountItems.end();
-            cppDeleteMountItems.erase(it, cppDeleteMountItems.end());
-
-            if (hasDeletedViewsWithSameTag) {
-              shouldCreateView = false;
-              LOG(ERROR)
-                  << "XIN: Detect DELETE...CREATE on the same tag from mutations in the same batch. The DELETE and CREATE mutations are removed before sending to the native platforms";
-            }
-          }
 
           if (shouldCreateView) {
             cppCommonMountItems.push_back(

packages/react-native/ReactAndroid/src/main/jni/react/fabric/FabricMountingManager.h

@@ -63,8 +63,6 @@ class FabricMountingManager final {
       allocatedViewRegistry_{};
   std::recursive_mutex allocatedViewsMutex_;
 
-  const bool reduceDeleteCreateMutation_{false};
-
   jni::local_ref<jobject> getProps(
       const ShadowView& oldShadowView,
       const ShadowView& newShadowView);