1a98374702
This change makes dart_library.js more resilient so it can run in a browser or in d8. This is a necessary step to later enable test.py dartdevk tests in d8. Change-Id: Ic8e5bbc9f1bbc6707a876208605f4fcaad41cee7 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/177000 Reviewed-by: Nicholas Shahan <nshahan@google.com> Reviewed-by: Mark Zhou <markzipan@google.com>