[vm,dart2wasm] Remove old TODO in convert_patch

The block right above the TODO comment does exactly what the comment
describes. Remove the comment.

Tested: comment-only change, tested by existing tests.
Change-Id: Ic33bca5873a0e3deb7b5bf817ebde93dcda760be
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/392360
Commit-Queue: Ömer Ağacan <omersa@google.com>
Reviewed-by: Lasse Nielsen <lrn@google.com>
diff --git a/sdk/lib/_internal/vm/lib/convert_patch.dart b/sdk/lib/_internal/vm/lib/convert_patch.dart
index 2c98bc9..7dee925 100644
--- a/sdk/lib/_internal/vm/lib/convert_patch.dart
+++ b/sdk/lib/_internal/vm/lib/convert_patch.dart
@@ -44,7 +44,6 @@
               (next as JsonDecoder)._reviver, this._allowMalformed)
           as dynamic/*=Converter<List<int>, T>*/;
     }
-    // TODO(lrn): Recognize a fused decoder where the next step is JsonDecoder.
     return super.fuse<T>(next);
   }
 }
diff --git a/sdk/lib/_internal/wasm/lib/convert_patch.dart b/sdk/lib/_internal/wasm/lib/convert_patch.dart
index 72c6ba7..fed6f6c 100644
--- a/sdk/lib/_internal/wasm/lib/convert_patch.dart
+++ b/sdk/lib/_internal/wasm/lib/convert_patch.dart
@@ -40,7 +40,6 @@
               (next as JsonDecoder)._reviver, this._allowMalformed)
           as dynamic/*=Converter<List<int>, T>*/;
     }
-    // TODO(lrn): Recognize a fused decoder where the next step is JsonDecoder.
     return super.fuse<T>(next);
   }
 }