Redo TimelineTask API

sdk/lib/_internal/js_runtime/lib/developer_patch.dart

Index: sdk/lib/_internal/js_runtime/lib/developer_patch.dart
diff --git a/sdk/lib/_internal/js_runtime/lib/developer_patch.dart b/sdk/lib/_internal/js_runtime/lib/developer_patch.dart
index 82b2c16edffb1e202942f77d6db1f65e2edc6c2e..003f269690ed9898cb9f4c93d28495ddf164c09b 100644
--- a/sdk/lib/_internal/js_runtime/lib/developer_patch.dart
+++ b/sdk/lib/_internal/js_runtime/lib/developer_patch.dart
@@ -62,6 +62,14 @@ void _reportCompleteEvent(int start,
 }
 
 @patch
+void _reportInstantEvent(int start,
+                         String category,
+                         String name,
+                         String argumentsAsJson) {
+  // TODO.
+}
+
+@patch
 int _getNextAsyncId() {
   return 0;
 }