fixes

Author: Emmanuel Garcia

shell/platform/android/io/flutter/plugin/platform/PlatformView.java

@@ -16,9 +16,8 @@ public interface PlatformView {
   View getView();
 
   /**
-   * Called by the {@link io.flutter.embedding.engine.FlutterEngine} that owns this {@code
-   * PlatformView} when the Android {@link View} responsible for rendering a Flutter UI is
-   * associated with the {@link io.flutter.embedding.engine.FlutterEngine}.
+   * Called when the {@link View} responsible for rendering a Flutter UI has been attached to a
+   * {@link io.flutter.embedding.engine.FlutterEngine}.
    *
    * <p>This means that our associated {@link io.flutter.embedding.engine.FlutterEngine} can now
    * render a UI and interact with the user.
@@ -34,9 +33,8 @@ public interface PlatformView {
   default void onFlutterViewAttached(@NonNull View flutterView) {}
 
   /**
-   * Called by the {@link io.flutter.embedding.engine.FlutterEngine} that owns this {@code
-   * PlatformView} when the Android {@link View} responsible for rendering a Flutter UI is detached
-   * and disassociated from the {@link io.flutter.embedding.engine.FlutterEngine}.
+   * Called when the {@link View} responsible for rendering a Flutter UI has been detached from the
+   * {@link io.flutter.embedding.engine.FlutterEngine}.
    *
    * <p>This means that our associated {@link io.flutter.embedding.engine.FlutterEngine} no longer
    * has a rendering surface, or a user interaction surface of any kind.

shell/platform/android/io/flutter/plugin/platform/PlatformViewsController.java

@@ -255,6 +255,7 @@ public long createForTextureLayer(
               });
           flutterView.addView(wrapperView);
           viewWrappers.append(viewId, wrapperView);
+          platformView.onFlutterViewAttached(flutterView);
           return txId;
         }
 
@@ -794,6 +795,7 @@ void initializePlatformViewIfNeeded(int viewId) {
 
     parentView.addView(embeddedView);
     flutterView.addView(parentView);
+    platformView.onFlutterViewAttached(flutterView);
   }
 
   public void attachToFlutterRenderer(@NonNull FlutterRenderer flutterRenderer) {

testing/scenario_app/android/app/src/main/java/dev/flutter/scenarios/TextPlatformView.java

@@ -22,16 +22,20 @@ public class TextPlatformView implements PlatformView {
     textView.setTextSize(72);
     textView.setBackgroundColor(Color.rgb(255, 255, 255));
     textView.setText(params);
+  }
 
+  @Override
+  public void onFlutterViewAttached(@NonNull View flutterView) {
     // Investigate why this is needed to make some gold tests pass.
     Choreographer.getInstance()
-        .postFrameCallback(
+        .postFrameCallbackDelayed(
             new Choreographer.FrameCallback() {
               @Override
               public void doFrame(long frameTimeNanos) {
                 textView.invalidate();
               }
-            });
+            },
+            500);
   }
 
   @Override