Generated dart code should import transitive imports.

mojo/dart/packages/_mojo_for_test_only/lib/sample/sample_factory.mojom.dart

Index: mojo/dart/packages/_mojo_for_test_only/lib/sample/sample_factory.mojom.dart
diff --git a/mojo/dart/packages/_mojo_for_test_only/lib/sample/sample_factory.mojom.dart b/mojo/dart/packages/_mojo_for_test_only/lib/sample/sample_factory.mojom.dart
index 708f8864c54e88eb21af82ace3ef8981ec734df5..062c242d51b3d7fa930f1735adb284f6c3a52fbc 100644
--- a/mojo/dart/packages/_mojo_for_test_only/lib/sample/sample_factory.mojom.dart
+++ b/mojo/dart/packages/_mojo_for_test_only/lib/sample/sample_factory.mojom.dart
@@ -1764,7 +1764,7 @@ 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);