* Roll dart to af1436931b.

Changes since last dart roll:

```
af1436931b (HEAD, origin/master, origin/HEAD) [CFE] Fix for insertion of duplicate NSM forwarders
48644d5f6a [CFE] Fix crash when trying to add NSM forwarder for a field
898260a998 Split dependency on dart:html from dart:js
ef919c5eb3 fix commit queue: update nSM test expectation on ddc too.
d014fce4de Update dartkp NSM expectations.
6bd38cc912 Analysis Server API for 'Extract Widget' refactoring.
123e59c189 Improve for loop recovery
790b7b98fb [kernel] Update more NSM expectations.
696be0ae46 Initial support for extracting methods.
8d669c9d4e [kernel] Update NSM-forwarding test expectations.
edf039d510 [ VM / Dart 2 ] Made StackMapGC test strong-mode clean. Fixes part of 32190.
77239ee1db [fuchsia] Replace use of deprecated fdio_get_vmo with fdio_get_vmo_clone.
```

* Update license hash. No changes to the licenses