The purpose of this refactoring is to provide a convenient way to
write JSON independently of VM service, which is excluded in PRODUCT
build mode.
Change-Id: I55700d9ead6ef9269a98714d8178f1edb35435cb
Reviewed-on: https://dart-review.googlesource.com/18502
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Alexander Markov