Revert "Reland: Call Dart plugin registrant if available (#25375)"

This reverts commit 7d34fdee.

lib/ui/hooks.dart

@@ -132,14 +132,10 @@ typedef _ListStringArgFunction(List<String> args);
 @pragma('vm:entry-point')
 // ignore: unused_element
 void _runMainZoned(Function startMainIsolateFunction,
-                   Function? dartPluginRegistrant,
                    Function userMainFunction,
                    List<String> args) {
   startMainIsolateFunction(() {
     runZonedGuarded<void>(() {
-      if (dartPluginRegistrant != null) {
-        dartPluginRegistrant();
-      }
       if (userMainFunction is _ListStringArgFunction) {
         (userMainFunction as dynamic)(args);
       } else {

runtime/dart_isolate.cc

@@ -700,7 +700,6 @@ bool DartIsolate::MarkIsolateRunnable() {
 
 [[nodiscard]] static bool InvokeMainEntrypoint(
     Dart_Handle user_entrypoint_function,
-    Dart_Handle plugin_registrant_function,
     Dart_Handle args) {
   if (tonic::LogIfError(user_entrypoint_function)) {
     FML_LOG(ERROR) << "Could not resolve main entrypoint function.";
@@ -718,8 +717,7 @@ bool DartIsolate::MarkIsolateRunnable() {
 
   if (tonic::LogIfError(tonic::DartInvokeField(
           Dart_LookupLibrary(tonic::ToDart("dart:ui")), "_runMainZoned",
-          {start_main_isolate_function, plugin_registrant_function,
-           user_entrypoint_function, args}))) {
+          {start_main_isolate_function, user_entrypoint_function, args}))) {
     FML_LOG(ERROR) << "Could not invoke the main entrypoint.";
     return false;
   }
@@ -744,34 +742,12 @@ bool DartIsolate::RunFromLibrary(std::optional<std::string> library_name,
   auto entrypoint_handle = entrypoint.has_value() && !entrypoint.value().empty()
                                ? tonic::ToDart(entrypoint.value().c_str())
                                : tonic::ToDart("main");
-  auto entrypoint_args = tonic::ToDart(args);
   auto user_entrypoint_function =
       ::Dart_GetField(library_handle, entrypoint_handle);
 
-  // The Dart plugin registrant is a function named `_registerPlugins`
-  // generated by the Flutter tool.
-  //
-  // This function binds a plugin implementation to their platform
-  // interface based on the configuration of the app's pubpec.yaml, and the
-  // plugin's pubspec.yaml.
-  //
-  // Since this function may or may not be defined. Check that it is a top
-  // level function, and call it in hooks.dart before the main entrypoint
-  // function.
-  //
-  // If it's not defined, then just call the main entrypoint function
-  // as usual.
-  //
-  // This allows embeddings to change the name of the entrypoint function.
-  auto plugin_registrant_function =
-      ::Dart_GetField(library_handle, tonic::ToDart("_registerPlugins"));
-
-  if (Dart_IsError(plugin_registrant_function)) {
-    plugin_registrant_function = Dart_Null();
-  }
-
-  if (!InvokeMainEntrypoint(user_entrypoint_function,
-                            plugin_registrant_function, entrypoint_args)) {
+  auto entrypoint_args = tonic::ToDart(args);
+
+  if (!InvokeMainEntrypoint(user_entrypoint_function, entrypoint_args)) {
     return false;
   }
 

runtime/dart_isolate_unittests.cc

@@ -613,39 +613,5 @@ TEST_F(DartIsolateTest, DISABLED_ValidLoadingUnitSucceeds) {
   Wait();
 }
 
-TEST_F(DartIsolateTest, DartPluginRegistrantIsCalled) {
-  ASSERT_FALSE(DartVMRef::IsInstanceRunning());
-
-  std::vector<std::string> messages;
-  fml::AutoResetWaitableEvent latch;
-
-  AddNativeCallback(
-      "PassMessage",
-      CREATE_NATIVE_ENTRY(([&latch, &messages](Dart_NativeArguments args) {
-        auto message = tonic::DartConverter<std::string>::FromDart(
-            Dart_GetNativeArgument(args, 0));
-        messages.push_back(message);
-        latch.Signal();
-      })));
-
-  const auto settings = CreateSettingsForFixture();
-  auto vm_ref = DartVMRef::Create(settings);
-  auto thread = CreateNewThread();
-  TaskRunners task_runners(GetCurrentTestName(),  //
-                           thread,                //
-                           thread,                //
-                           thread,                //
-                           thread                 //
-  );
-  auto isolate = RunDartCodeInIsolate(vm_ref, settings, task_runners,
-                                      "mainForPluginRegistrantTest", {},
-                                      GetFixturesPath());
-  ASSERT_TRUE(isolate);
-  ASSERT_EQ(isolate->get()->GetPhase(), DartIsolate::Phase::Running);
-  latch.Wait();
-  ASSERT_EQ(messages.size(), 1u);
-  ASSERT_EQ(messages[0], "_registerPlugins was called");
-}
-
 }  // namespace testing
 }  // namespace flutter

runtime/fixtures/runtime_test.dart

@@ -10,7 +10,8 @@ import 'dart:ui';
 
 import 'split_lib_test.dart' deferred as splitlib;
 
-void main() {}
+void main() {
+}
 
 @pragma('vm:entry-point')
 void sayHi() {
@@ -114,24 +115,3 @@ void testCanConvertListOfInts(List<int> args){
                 args[2] == 3 &&
                 args[3] == 4);
 }
-
-bool didCallRegistrantBeforeEntrypoint = false;
-
-// Test the Dart plugin registrant.
-// _registerPlugins requires the entrypoint annotation, so the compiler doesn't tree shake it.
-@pragma('vm:entry-point')
-void _registerPlugins() { // ignore: unused_element
-  if (didCallRegistrantBeforeEntrypoint) {
-    throw '_registerPlugins is being called twice';
-  }
-  didCallRegistrantBeforeEntrypoint = true;
-}
-
-@pragma('vm:entry-point')
-void mainForPluginRegistrantTest() { // ignore: unused_element
-  if (didCallRegistrantBeforeEntrypoint) {
-    passMessage('_registerPlugins was called');
-  } else {
-    passMessage('_registerPlugins was not called');
-  }
-}