Mojom compiler frontend: Change the type of the |offset| field to uint32.

mojom/mojom_tool/serialization/serialization.go

Index: mojom/mojom_tool/serialization/serialization.go
diff --git a/mojom/mojom_tool/serialization/serialization.go b/mojom/mojom_tool/serialization/serialization.go
index 2c479714032722de4640b5a4e1785b035a2da3be..c7d10eb5d7b5c1a8d35cdcf89e9ea9675aade40a 100644
--- a/mojom/mojom_tool/serialization/serialization.go
+++ b/mojom/mojom_tool/serialization/serialization.go
@@ -322,9 +322,7 @@ func translateStructField(f *mojom.StructField) (field mojom_types.StructField)
 		field.DefaultValue = translateDefaultFieldValue(f.DefaultValue)
 	}
 	if emitComputedPackingData {
-		// TODO(rudominer) Check the allowed size of offsets. The type used in
-		// mojom_types.mojom might need to be changed.
-		field.Offset = int32(f.Offset())
+		field.Offset = f.Offset()
 		field.Bit = int8(f.Bit())
 		field.MinVersion = f.MinVersion()
 	}