Review comments

Author: jcollins-g

tool/grind.dart

@@ -959,6 +959,8 @@ Future<void> testDartdocFlutterPlugin() async {
 @Task('Validate the SDK doc build.')
 @Depends(buildSdkDocs)
 void validateSdkDocs() {
+  // TODO(jcollins-g): Remove flexibility in library counts once dev build
+  // includes https://dart-review.googlesource.com/c/sdk/+/93160
   const expectedLibCounts = [0, 1];
   const expectedSubLibCount = [19, 20];
   const expectedTotalCount = [19, 20];