Generated dart code should import transitive imports.

mojo/dart/packages/_mojo_for_test_only/lib/dart_to_cpp/dart_to_cpp.mojom.dart

Index: mojo/dart/packages/_mojo_for_test_only/lib/dart_to_cpp/dart_to_cpp.mojom.dart
diff --git a/mojo/dart/packages/_mojo_for_test_only/lib/dart_to_cpp/dart_to_cpp.mojom.dart b/mojo/dart/packages/_mojo_for_test_only/lib/dart_to_cpp/dart_to_cpp.mojom.dart
index 6ce4364d2d1a4da5884bf86b76f234d267415b85..e364cb0b971258c7469013dd9c15792c7ae0b947 100644
--- a/mojo/dart/packages/_mojo_for_test_only/lib/dart_to_cpp/dart_to_cpp.mojom.dart
+++ b/mojo/dart/packages/_mojo_for_test_only/lib/dart_to_cpp/dart_to_cpp.mojom.dart
@@ -1331,7 +1331,7 @@ 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);