Return more eagerly when toggling service extensions (#162774)

Fixes flutter/devtools#8497

When handling requests to enable or disable service extensions, we
currently wait until the next frame is rendered before responding to the
request. If the app is hidden this will not happen until the app is
unhidden, or a frame is scheduled for some other reason.

This fix does not await the next frame before responding - which I think
is reasonable - but feel free to push back if there is a reason to not
do it that way.

Updated tests to expect the response before actually rendering the next
frame.

## Pre-launch Checklist

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there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

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on [Discord].

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Author: jakemac53

packages/flutter/lib/src/rendering/binding.dart

@@ -9,6 +9,7 @@
 /// @docImport 'layer.dart';
 library;
 
+import 'dart:async';
 import 'dart:ui' as ui show PictureRecorder, SceneBuilder, SemanticsUpdate;
 
 import 'package:flutter/foundation.dart';
@@ -85,43 +86,49 @@ mixin RendererBinding
         setter: (bool value) async {
           if (debugInvertOversizedImages != value) {
             debugInvertOversizedImages = value;
-            return _forceRepaint();
+            // We don't want to block the vm service response on the frame
+            // actually rendering, just schedule it and return;
+            unawaited(_forceRepaint());
           }
-          return Future<void>.value();
         },
       );
       registerBoolServiceExtension(
         name: RenderingServiceExtensions.debugPaint.name,
         getter: () async => debugPaintSizeEnabled,
-        setter: (bool value) {
+        setter: (bool value) async {
           if (debugPaintSizeEnabled == value) {
-            return Future<void>.value();
+            return;
           }
           debugPaintSizeEnabled = value;
-          return _forceRepaint();
+          // We don't want to block the vm service response on the frame
+          // actually rendering, just schedule it and return;
+          unawaited(_forceRepaint());
         },
       );
       registerBoolServiceExtension(
         name: RenderingServiceExtensions.debugPaintBaselinesEnabled.name,
         getter: () async => debugPaintBaselinesEnabled,
-        setter: (bool value) {
+        setter: (bool value) async {
           if (debugPaintBaselinesEnabled == value) {
-            return Future<void>.value();
+            return;
           }
           debugPaintBaselinesEnabled = value;
-          return _forceRepaint();
+          // We don't want to block the vm service response on the frame
+          // actually rendering, just schedule it and return;
+          unawaited(_forceRepaint());
         },
       );
       registerBoolServiceExtension(
         name: RenderingServiceExtensions.repaintRainbow.name,
         getter: () async => debugRepaintRainbowEnabled,
-        setter: (bool value) {
+        setter: (bool value) async {
           final bool repaint = debugRepaintRainbowEnabled && !value;
           debugRepaintRainbowEnabled = value;
           if (repaint) {
-            return _forceRepaint();
+            // We don't want to block the vm service response on the frame
+            // actually rendering, just schedule it and return;
+            unawaited(_forceRepaint());
           }
-          return Future<void>.value();
         },
       );
       registerServiceExtension(
@@ -133,34 +140,40 @@ mixin RendererBinding
       registerBoolServiceExtension(
         name: RenderingServiceExtensions.debugDisableClipLayers.name,
         getter: () async => debugDisableClipLayers,
-        setter: (bool value) {
+        setter: (bool value) async {
           if (debugDisableClipLayers == value) {
-            return Future<void>.value();
+            return;
           }
           debugDisableClipLayers = value;
-          return _forceRepaint();
+          // We don't want to block the vm service response on the frame
+          // actually rendering, just schedule it and return;
+          unawaited(_forceRepaint());
         },
       );
       registerBoolServiceExtension(
         name: RenderingServiceExtensions.debugDisablePhysicalShapeLayers.name,
         getter: () async => debugDisablePhysicalShapeLayers,
-        setter: (bool value) {
+        setter: (bool value) async {
           if (debugDisablePhysicalShapeLayers == value) {
-            return Future<void>.value();
+            return;
           }
           debugDisablePhysicalShapeLayers = value;
-          return _forceRepaint();
+          // We don't want to block the vm service response on the frame
+          // actually rendering, just schedule it and return;
+          unawaited(_forceRepaint());
         },
       );
       registerBoolServiceExtension(
         name: RenderingServiceExtensions.debugDisableOpacityLayers.name,
         getter: () async => debugDisableOpacityLayers,
-        setter: (bool value) {
+        setter: (bool value) async {
           if (debugDisableOpacityLayers == value) {
-            return Future<void>.value();
+            return;
           }
           debugDisableOpacityLayers = value;
-          return _forceRepaint();
+          // We don't want to block the vm service response on the frame
+          // actually rendering, just schedule it and return;
+          unawaited(_forceRepaint());
         },
       );
       return true;

packages/flutter/test/foundation/service_extensions_test.dart

@@ -413,7 +413,7 @@ void main() {
     });
     await binding.flushMicrotasks();
     expect(binding.frameScheduled, isTrue);
-    expect(completed, isFalse);
+    expect(completed, isTrue);
     await binding.doFrame();
     await binding.flushMicrotasks();
     expect(completed, isTrue);
@@ -484,7 +484,7 @@ void main() {
     });
     await binding.flushMicrotasks();
     expect(binding.frameScheduled, isTrue);
-    expect(completed, isFalse);
+    expect(completed, isTrue);
     await binding.doFrame();
     await binding.flushMicrotasks();
     expect(completed, isTrue);
@@ -546,7 +546,7 @@ void main() {
     });
     await binding.flushMicrotasks();
     expect(binding.frameScheduled, isTrue);
-    expect(completed, isFalse);
+    expect(completed, isTrue);
     await binding.doFrame();
     await binding.flushMicrotasks();
     expect(completed, isTrue);
@@ -1038,7 +1038,7 @@ void main() {
       completed = true;
     });
     await binding.flushMicrotasks();
-    expect(completed, false);
+    expect(completed, isTrue);
     expect(binding.frameScheduled, isTrue);
     await binding.doFrame();
     await binding.flushMicrotasks();
@@ -1082,7 +1082,7 @@ void main() {
     });
     await binding.flushMicrotasks();
     expect(binding.frameScheduled, isTrue);
-    expect(completed, isFalse);
+    expect(completed, isTrue);
     await binding.doFrame();
     await binding.flushMicrotasks();
     expect(completed, isTrue);
@@ -1143,7 +1143,7 @@ void main() {
     });
     await binding.flushMicrotasks();
     expect(binding.frameScheduled, isTrue);
-    expect(completed, isFalse);
+    expect(completed, isTrue);
     await binding.doFrame();
     await binding.flushMicrotasks();
     expect(completed, isTrue);
@@ -1204,7 +1204,7 @@ void main() {
     });
     await binding.flushMicrotasks();
     expect(binding.frameScheduled, isTrue);
-    expect(completed, isFalse);
+    expect(completed, isTrue);
     await binding.doFrame();
     await binding.flushMicrotasks();
     expect(completed, isTrue);