Roll out turbo_module_binding_mode experiment

Summary:
We ran an experiment to test different implementations of TurboModules HostObjects, as the current one has various inefficiencies, such as re-creating HostFunctions on every property access. The strategy we found to be most efficient and flexible longer-term is to represent the TurboModule with a plain JavaScript object and use a HostObject as its prototype. Whenever a property is accessed through the prototype, we cache the property value on the plain object, so it can be efficiently resolved by the VM for future accesses.

Changelog: [Internal]

Reviewed By: NickGerleman

Differential Revision: D38355134

fbshipit-source-id: 59253091412d0c6827ad7a4b1ac7dc0c7fe89cc2

ReactAndroid/src/main/java/com/facebook/react/config/ReactFeatureFlags.java

@@ -116,17 +116,6 @@ public class ReactFeatureFlags {
   /** Feature Flag to control RN Android scrollEventThrottle prop. */
   public static boolean enableScrollEventThrottle = false;
 
-  /**
-   * Feature flag that controls how turbo modules are exposed to JS
-   *
-   * <ul>
-   *   <li>0 = as a HostObject
-   *   <li>1 = as a plain object, backed with a HostObject as prototype
-   *   <li>2 = as a plain object, with all methods eagerly configured
-   * </ul>
-   */
-  public static int turboModuleBindingMode = 0;
-
   /**
    * Feature Flag to enable View Recycling. When enabled, individual ViewManagers must still opt-in.
    */

ReactAndroid/src/main/java/com/facebook/react/turbomodule/core/jni/ReactCommon/TurboModuleManager.cpp

@@ -20,17 +20,6 @@
 namespace facebook {
 namespace react {
 
-constexpr static auto ReactFeatureFlagsJavaDescriptor =
-    "com/facebook/react/config/ReactFeatureFlags";
-
-static int getFeatureFlagValue(const char *name) {
-  static const auto reactFeatureFlagsJavaDescriptor =
-      jni::findClassStatic(ReactFeatureFlagsJavaDescriptor);
-  const auto field =
-      reactFeatureFlagsJavaDescriptor->getStaticField<jint>(name);
-  return reactFeatureFlagsJavaDescriptor->getStaticFieldValue(field);
-}
-
 TurboModuleManager::TurboModuleManager(
     jni::alias_ref<TurboModuleManager::javaobject> jThis,
     RuntimeExecutor runtimeExecutor,
@@ -180,13 +169,8 @@ void TurboModuleManager::installJSIBindings() {
       return nullptr;
     };
 
-    TurboModuleBindingMode bindingMode = static_cast<TurboModuleBindingMode>(
-        getFeatureFlagValue("turboModuleBindingMode"));
     TurboModuleBinding::install(
-        runtime,
-        std::move(turboModuleProvider),
-        bindingMode,
-        longLivedObjectCollection_);
+        runtime, std::move(turboModuleProvider), longLivedObjectCollection_);
   });
 }