Let the inferrer know that lazy variables can also be null incase their initializer throws.

sdk/lib/_internal/compiler/implementation/compile_time_constants.dart

Index: sdk/lib/_internal/compiler/implementation/compile_time_constants.dart
===================================================================
--- sdk/lib/_internal/compiler/implementation/compile_time_constants.dart	(revision 27658)
+++ sdk/lib/_internal/compiler/implementation/compile_time_constants.dart	(working copy)
@@ -205,7 +205,7 @@
                   node, MessageKind.NOT_ASSIGNABLE.error,
                   {'fromType': constantType, 'toType': elementType});
             } else {
-              // If the field can be lazily initialized, we will throw
+              // If the field cannot be lazily initialized, we will throw
               // the exception at runtime.
               value = null;
             }