Reland "Remove usage of Dart_AllocateWithNativeFields"

lib/ui/compositing.dart

@@ -280,12 +280,14 @@ class SceneBuilder extends NativeFieldWrapperClass2 {
   }) {
     assert(_matrix4IsValid(matrix4));
     assert(_debugCheckCanBeUsedAsOldLayer(oldLayer, 'pushTransform'));
-    final TransformEngineLayer layer = TransformEngineLayer._(_pushTransform(matrix4));
+    final EngineLayer engineLayer = EngineLayer._();
+    _pushTransform(engineLayer, matrix4);
+    final TransformEngineLayer layer = TransformEngineLayer._(engineLayer);
     assert(_debugPushLayer(layer));
     return layer;
   }
 
-  EngineLayer _pushTransform(Float64List matrix4) native 'SceneBuilder_pushTransform';
+  void _pushTransform(EngineLayer layer, Float64List matrix4) native 'SceneBuilder_pushTransform';
 
   /// Pushes an offset operation onto the operation stack.
   ///
@@ -302,12 +304,14 @@ class SceneBuilder extends NativeFieldWrapperClass2 {
     OffsetEngineLayer oldLayer,
   }) {
     assert(_debugCheckCanBeUsedAsOldLayer(oldLayer, 'pushOffset'));
-    final OffsetEngineLayer layer = OffsetEngineLayer._(_pushOffset(dx, dy));
+    final EngineLayer engineLayer = EngineLayer._();
+    _pushOffset(engineLayer, dx, dy);
+    final OffsetEngineLayer layer = OffsetEngineLayer._(engineLayer);
     assert(_debugPushLayer(layer));
     return layer;
   }
 
-  EngineLayer _pushOffset(double dx, double dy) native 'SceneBuilder_pushOffset';
+  void _pushOffset(EngineLayer layer, double dx, double dy) native 'SceneBuilder_pushOffset';
 
   /// Pushes a rectangular clip operation onto the operation stack.
   ///
@@ -327,13 +331,14 @@ class SceneBuilder extends NativeFieldWrapperClass2 {
     assert(clipBehavior != null);
     assert(clipBehavior != Clip.none);
     assert(_debugCheckCanBeUsedAsOldLayer(oldLayer, 'pushClipRect'));
-    final ClipRectEngineLayer layer = ClipRectEngineLayer._(
-        _pushClipRect(rect.left, rect.right, rect.top, rect.bottom, clipBehavior.index));
+    final EngineLayer engineLayer = EngineLayer._();
+    _pushClipRect(engineLayer, rect.left, rect.right, rect.top, rect.bottom, clipBehavior.index);
+    final ClipRectEngineLayer layer = ClipRectEngineLayer._(engineLayer);
     assert(_debugPushLayer(layer));
     return layer;
   }
 
-  EngineLayer _pushClipRect(double left, double right, double top, double bottom, int clipBehavior)
+  void _pushClipRect(EngineLayer outEngineLayer, double left, double right, double top, double bottom, int clipBehavior)
       native 'SceneBuilder_pushClipRect';
 
   /// Pushes a rounded-rectangular clip operation onto the operation stack.
@@ -354,13 +359,14 @@ class SceneBuilder extends NativeFieldWrapperClass2 {
     assert(clipBehavior != null);
     assert(clipBehavior != Clip.none);
     assert(_debugCheckCanBeUsedAsOldLayer(oldLayer, 'pushClipRRect'));
-    final ClipRRectEngineLayer layer =
-        ClipRRectEngineLayer._(_pushClipRRect(rrect._value32, clipBehavior.index));
+    final EngineLayer engineLayer = EngineLayer._();
+    _pushClipRRect(engineLayer, rrect._value32, clipBehavior.index);
+    final ClipRRectEngineLayer layer = ClipRRectEngineLayer._(engineLayer);
     assert(_debugPushLayer(layer));
     return layer;
   }
 
-  EngineLayer _pushClipRRect(Float32List rrect, int clipBehavior)
+  void _pushClipRRect(EngineLayer layer, Float32List rrect, int clipBehavior)
       native 'SceneBuilder_pushClipRRect';
 
   /// Pushes a path clip operation onto the operation stack.
@@ -381,13 +387,14 @@ class SceneBuilder extends NativeFieldWrapperClass2 {
     assert(clipBehavior != null);
     assert(clipBehavior != Clip.none);
     assert(_debugCheckCanBeUsedAsOldLayer(oldLayer, 'pushClipPath'));
-    final ClipPathEngineLayer layer =
-        ClipPathEngineLayer._(_pushClipPath(path, clipBehavior.index));
+    final EngineLayer engineLayer = EngineLayer._();
+    _pushClipPath(engineLayer, path, clipBehavior.index);
+    final ClipPathEngineLayer layer = ClipPathEngineLayer._(engineLayer);
     assert(_debugPushLayer(layer));
     return layer;
   }
 
-  EngineLayer _pushClipPath(Path path, int clipBehavior) native 'SceneBuilder_pushClipPath';
+  void _pushClipPath(EngineLayer layer, Path path, int clipBehavior) native 'SceneBuilder_pushClipPath';
 
   /// Pushes an opacity operation onto the operation stack.
   ///
@@ -407,13 +414,14 @@ class SceneBuilder extends NativeFieldWrapperClass2 {
     OpacityEngineLayer oldLayer,
   }) {
     assert(_debugCheckCanBeUsedAsOldLayer(oldLayer, 'pushOpacity'));
-    final OpacityEngineLayer layer =
-        OpacityEngineLayer._(_pushOpacity(alpha, offset.dx, offset.dy));
+    final EngineLayer engineLayer = EngineLayer._();
+    _pushOpacity(engineLayer, alpha, offset.dx, offset.dy);
+    final OpacityEngineLayer layer = OpacityEngineLayer._(engineLayer);
     assert(_debugPushLayer(layer));
     return layer;
   }
 
-  EngineLayer _pushOpacity(int alpha, double dx, double dy) native 'SceneBuilder_pushOpacity';
+  void _pushOpacity(EngineLayer layer, int alpha, double dx, double dy) native 'SceneBuilder_pushOpacity';
 
   /// Pushes a color filter operation onto the operation stack.
   ///
@@ -433,12 +441,14 @@ class SceneBuilder extends NativeFieldWrapperClass2 {
     assert(_debugCheckCanBeUsedAsOldLayer(oldLayer, 'pushColorFilter'));
     final _ColorFilter nativeFilter = filter._toNativeColorFilter();
     assert(nativeFilter != null);
-    final ColorFilterEngineLayer layer = ColorFilterEngineLayer._(_pushColorFilter(nativeFilter));
+    final EngineLayer engineLayer = EngineLayer._();
+    _pushColorFilter(engineLayer, nativeFilter);
+    final ColorFilterEngineLayer layer = ColorFilterEngineLayer._(engineLayer);
     assert(_debugPushLayer(layer));
     return layer;
   }
 
-  EngineLayer _pushColorFilter(_ColorFilter filter) native 'SceneBuilder_pushColorFilter';
+  void _pushColorFilter(EngineLayer layer, _ColorFilter filter) native 'SceneBuilder_pushColorFilter';
 
   /// Pushes an image filter operation onto the operation stack.
   ///
@@ -458,12 +468,14 @@ class SceneBuilder extends NativeFieldWrapperClass2 {
     assert(_debugCheckCanBeUsedAsOldLayer(oldLayer, 'pushImageFilter'));
     final _ImageFilter nativeFilter = filter._toNativeImageFilter();
     assert(nativeFilter != null);
-    final ImageFilterEngineLayer layer = ImageFilterEngineLayer._(_pushImageFilter(nativeFilter));
+    final EngineLayer engineLayer = EngineLayer._();
+    _pushImageFilter(engineLayer, nativeFilter);
+    final ImageFilterEngineLayer layer = ImageFilterEngineLayer._(engineLayer);
     assert(_debugPushLayer(layer));
     return layer;
   }
 
-  EngineLayer _pushImageFilter(_ImageFilter filter) native 'SceneBuilder_pushImageFilter';
+  void _pushImageFilter(EngineLayer outEngineLayer, _ImageFilter filter) native 'SceneBuilder_pushImageFilter';
 
   /// Pushes a backdrop filter operation onto the operation stack.
   ///
@@ -480,13 +492,14 @@ class SceneBuilder extends NativeFieldWrapperClass2 {
     BackdropFilterEngineLayer oldLayer,
   }) {
     assert(_debugCheckCanBeUsedAsOldLayer(oldLayer, 'pushBackdropFilter'));
-    final BackdropFilterEngineLayer layer =
-        BackdropFilterEngineLayer._(_pushBackdropFilter(filter._toNativeImageFilter()));
+    final EngineLayer engineLayer = EngineLayer._();
+    _pushBackdropFilter(engineLayer, filter._toNativeImageFilter());
+    final BackdropFilterEngineLayer layer = BackdropFilterEngineLayer._(engineLayer);
     assert(_debugPushLayer(layer));
     return layer;
   }
 
-  EngineLayer _pushBackdropFilter(_ImageFilter filter) native 'SceneBuilder_pushBackdropFilter';
+  void _pushBackdropFilter(EngineLayer outEngineLayer, _ImageFilter filter) native 'SceneBuilder_pushBackdropFilter';
 
   /// Pushes a shader mask operation onto the operation stack.
   ///
@@ -505,13 +518,23 @@ class SceneBuilder extends NativeFieldWrapperClass2 {
     ShaderMaskEngineLayer oldLayer,
   }) {
     assert(_debugCheckCanBeUsedAsOldLayer(oldLayer, 'pushShaderMask'));
-    final ShaderMaskEngineLayer layer = ShaderMaskEngineLayer._(_pushShaderMask(
-        shader, maskRect.left, maskRect.right, maskRect.top, maskRect.bottom, blendMode.index));
+    final EngineLayer engineLayer = EngineLayer._();
+    _pushShaderMask(
+      engineLayer,
+      shader,
+      maskRect.left,
+      maskRect.right,
+      maskRect.top,
+      maskRect.bottom,
+      blendMode.index,
+    );
+    final ShaderMaskEngineLayer layer = ShaderMaskEngineLayer._(engineLayer);
     assert(_debugPushLayer(layer));
     return layer;
   }
 
   EngineLayer _pushShaderMask(
+      EngineLayer engineLayer,
       Shader shader,
       double maskRectLeft,
       double maskRectRight,
@@ -545,13 +568,21 @@ class SceneBuilder extends NativeFieldWrapperClass2 {
     PhysicalShapeEngineLayer oldLayer,
   }) {
     assert(_debugCheckCanBeUsedAsOldLayer(oldLayer, 'pushPhysicalShape'));
-    final PhysicalShapeEngineLayer layer = PhysicalShapeEngineLayer._(_pushPhysicalShape(
-        path, elevation, color.value, shadowColor?.value ?? 0xFF000000, clipBehavior.index));
+    final EngineLayer engineLayer = EngineLayer._();
+    _pushPhysicalShape(
+      engineLayer,
+      path,
+      elevation,
+      color.value,
+      shadowColor?.value ?? 0xFF000000,
+      clipBehavior.index,
+    );
+    final PhysicalShapeEngineLayer layer = PhysicalShapeEngineLayer._(engineLayer);
     assert(_debugPushLayer(layer));
     return layer;
   }
 
-  EngineLayer _pushPhysicalShape(Path path, double elevation, int color, int shadowColor,
+  EngineLayer _pushPhysicalShape(EngineLayer outEngineLayer, Path path, double elevation, int color, int shadowColor,
       int clipBehavior) native 'SceneBuilder_pushPhysicalShape';
 
   /// Ends the effect of the most recently pushed operation.
@@ -769,7 +800,13 @@ class SceneBuilder extends NativeFieldWrapperClass2 {
   ///
   /// After calling this function, the scene builder object is invalid and
   /// cannot be used further.
-  Scene build() native 'SceneBuilder_build';
+  Scene build() {
+    final Scene scene = Scene._();
+    _build(scene);
+    return scene;
+  }
+
+  void _build(Scene outScene) native 'SceneBuilder_build';
 }
 
 /// (Fuchsia-only) Hosts content provided by another application.

lib/ui/compositing/scene.cc

@@ -26,13 +26,15 @@ IMPLEMENT_WRAPPERTYPEINFO(ui, Scene);
 
 DART_BIND_ALL(Scene, FOR_EACH_BINDING)
 
-fml::RefPtr<Scene> Scene::create(std::shared_ptr<flutter::Layer> rootLayer,
-                                 uint32_t rasterizerTracingThreshold,
-                                 bool checkerboardRasterCacheImages,
-                                 bool checkerboardOffscreenLayers) {
-  return fml::MakeRefCounted<Scene>(
+void Scene::create(Dart_Handle scene_handle,
+                   std::shared_ptr<flutter::Layer> rootLayer,
+                   uint32_t rasterizerTracingThreshold,
+                   bool checkerboardRasterCacheImages,
+                   bool checkerboardOffscreenLayers) {
+  auto scene = fml::MakeRefCounted<Scene>(
       std::move(rootLayer), rasterizerTracingThreshold,
       checkerboardRasterCacheImages, checkerboardOffscreenLayers);
+  scene->ClaimDartHandle(scene_handle);
 }
 
 Scene::Scene(std::shared_ptr<flutter::Layer> rootLayer,

lib/ui/compositing/scene.h

@@ -24,10 +24,11 @@ class Scene : public RefCountedDartWrappable<Scene> {
 
  public:
   ~Scene() override;
-  static fml::RefPtr<Scene> create(std::shared_ptr<flutter::Layer> rootLayer,
-                                   uint32_t rasterizerTracingThreshold,
-                                   bool checkerboardRasterCacheImages,
-                                   bool checkerboardOffscreenLayers);
+  static void create(Dart_Handle scene_handle,
+                     std::shared_ptr<flutter::Layer> rootLayer,
+                     uint32_t rasterizerTracingThreshold,
+                     bool checkerboardRasterCacheImages,
+                     bool checkerboardOffscreenLayers);
 
   std::unique_ptr<flutter::LayerTree> takeLayerTree();