Mojom frontend: Correctly handle empty structs in computeVersionInfo()

mojo/dart/packages/_mojo_for_test_only/lib/imported/sample_import.mojom.dart

Index: mojo/dart/packages/_mojo_for_test_only/lib/imported/sample_import.mojom.dart
diff --git a/mojo/dart/packages/_mojo_for_test_only/lib/imported/sample_import.mojom.dart b/mojo/dart/packages/_mojo_for_test_only/lib/imported/sample_import.mojom.dart
index c682f00c14155422581e28d8436bc4f0ed579036..225d4df4840c532a6df72d5cbc79bf8f31ba9b3e 100644
--- a/mojo/dart/packages/_mojo_for_test_only/lib/imported/sample_import.mojom.dart
+++ b/mojo/dart/packages/_mojo_for_test_only/lib/imported/sample_import.mojom.dart
@@ -542,7 +542,7 @@ mojom_types.RuntimeTypeInfo  _initRuntimeTypeInfo() {
   // serializedRuntimeTypeInfo contains the bytes of the Mojo serialization of
   // a mojom_types.RuntimeTypeInfo struct describing the Mojom types in this
   // file. The string contains the base64 encoding of the gzip-compressed bytes.
-  var serializedRuntimeTypeInfo = "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";
+  var serializedRuntimeTypeInfo = "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";
 
   // Deserialize RuntimeTypeInfo
   var bytes = BASE64.decode(serializedRuntimeTypeInfo);