[macOS] Move to new present callback (flutter/engine#51436)

Migrates the macOS embedder to the new present callback which includes a `view_id` value.

Not much can be tested, since this doesn't change any features, nor add any features without the ability to add a view. But I added a test to verify that rendering to an unknown view is a graceful no-op.

Design doc: https://flutter.dev/go/multi-view-embedder-apis

Part of https://github.com/flutter/flutter/issues/144810
Part of https://github.com/flutter/flutter/issues/142845

[C++, Objective-C, Java style guides]: https://github.com/flutter/engine/blob/main/CONTRIBUTING.md#style

engine/src/flutter/shell/platform/darwin/macos/framework/Source/FlutterEngine.mm

@@ -847,15 +847,9 @@ static void SetThreadPriority(FlutterThreadPriority priority) {
                                                   void* user_data                            //
                                                ) { return true; };
 
-  _compositor.present_layers_callback = [](const FlutterLayer** layers,  //
-                                           size_t layers_count,          //
-                                           void* user_data               //
-                                        ) {
-    // TODO(dkwingsmt): This callback only supports single-view, therefore it
-    // only operates on the implicit view. To support multi-view, we need a new
-    // callback that also receives a view ID.
-    return reinterpret_cast<flutter::FlutterCompositor*>(user_data)->Present(kFlutterImplicitViewId,
-                                                                             layers, layers_count);
+  _compositor.present_view_callback = [](const FlutterPresentViewInfo* info) {
+    return reinterpret_cast<flutter::FlutterCompositor*>(info->user_data)
+        ->Present(info->view_id, info->layers, info->layers_count);
   };
 
   _compositor.avoid_backing_store_cache = true;

engine/src/flutter/shell/platform/darwin/macos/framework/Source/FlutterEngineTest.mm

@@ -535,7 +535,56 @@ TEST_F(FlutterEngineTest, Compositor) {
   // TODO(gw280): add support for screenshot tests in this test harness
 
   [engine shutDownEngine];
-}  // namespace flutter::testing
+}
+
+TEST_F(FlutterEngineTest, CompositorIgnoresUnknownView) {
+  FlutterEngine* engine = GetFlutterEngine();
+  auto original_init = engine.embedderAPI.Initialize;
+  ::FlutterCompositor compositor;
+  engine.embedderAPI.Initialize = MOCK_ENGINE_PROC(
+      Initialize, ([&compositor, &original_init](
+                       size_t version, const FlutterRendererConfig* config,
+                       const FlutterProjectArgs* args, void* user_data, auto engine_out) {
+        compositor = *args->compositor;
+        return original_init(version, config, args, user_data, engine_out);
+      }));
+
+  FlutterViewController* viewController = [[FlutterViewController alloc] initWithEngine:engine
+                                                                                nibName:nil
+                                                                                 bundle:nil];
+  [viewController loadView];
+
+  EXPECT_TRUE([engine runWithEntrypoint:@"empty"]);
+
+  FlutterBackingStoreConfig config = {
+      .struct_size = sizeof(FlutterBackingStoreConfig),
+      .size = FlutterSize{10, 10},
+  };
+  FlutterBackingStore backing_store = {};
+  EXPECT_NE(compositor.create_backing_store_callback, nullptr);
+  EXPECT_TRUE(
+      compositor.create_backing_store_callback(&config, &backing_store, compositor.user_data));
+
+  FlutterLayer layer{
+      .type = kFlutterLayerContentTypeBackingStore,
+      .backing_store = &backing_store,
+  };
+  std::vector<FlutterLayer*> layers = {&layer};
+
+  FlutterPresentViewInfo info = {
+      .struct_size = sizeof(FlutterPresentViewInfo),
+      .view_id = 123,
+      .layers = const_cast<const FlutterLayer**>(layers.data()),
+      .layers_count = 1,
+      .user_data = compositor.user_data,
+  };
+  EXPECT_NE(compositor.present_view_callback, nullptr);
+  EXPECT_FALSE(compositor.present_view_callback(&info));
+  EXPECT_TRUE(compositor.collect_backing_store_callback(&backing_store, compositor.user_data));
+
+  (void)viewController;
+  [engine shutDownEngine];
+}
 
 TEST_F(FlutterEngineTest, DartEntrypointArguments) {
   NSString* fixtures = @(flutter::testing::GetFixturesPath());

engine/src/flutter/shell/platform/darwin/macos/framework/Source/fixtures/flutter_desktop_test.dart

@@ -12,6 +12,10 @@ external void signalNativeTest();
 void main() {
 }
 
+@pragma('vm:entry-point')
+void empty() {
+}
+
 /// Notifies the test of a string value.
 ///
 /// This is used to notify the native side of the test of a string value from