e1b8c6890c
This CL adds the ability to initialize the Dart Application class with a shell proxy (rather than with a MojoHandle). This change lets Sky use the Dart bindings for Mojo. This CL was reviewed on the SkyDart branch in https://codereview.chromium.org/919883002/ R=zra@google.com, zra@chromium.org Review URL: https://codereview.chromium.org/922083002