This change further prepares for the removal of Observatory from the
shipped Dart SDK by creating a fork to be used by the remaining
Observatory users.
This is basically a straight copy of the contents from
runtime/observatory with the exception of two new scripts:
- `bin/observatory.dart`, a utility to launch Observatory
- `bin/activate.dart`, which globally activates `bin/observatory.dart`
as `observatory`
This change also updates the presubmits to ensure that
`runtime/observatory` is effectively placed in read-only mode to prevent
any divergences with the fork.
Work towards https://github.com/dart-lang/sdk/issues/50233
Change-Id: Iff3a7512058f36afa2a96d45d94a1dff424401d6
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/429800
Reviewed-by: Siva Annamalai <asiva@google.com>
Commit-Queue: Ben Konyi <bkonyi@google.com>
Ben Konyi