Replace modelled Dart code comments with Kernel text validation.
Replace modelled Dart code comments with Kernel text validation.

Paul, do you want to keep ASCII hierarchies, or the text provides
enough information / easy to read?

R=ahe@google.com, paulberry@google.com
BUG=

Review-Url: https://codereview.chromium.org/2920563002 .

dart-archive/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dartino/dart-sdk,dart-lang/sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dartino/dart-sdk,dart-lang/sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dart-lang/sdk,dartino/dart-sdk,dartino/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dart-archive/dart-sdk,dartino/dart-sdk