[co19] Roll co19 to ca44d7a864e0fb9d214be16818f56a485ab778c1
[co19] Roll co19 to ca44d7a864e0fb9d214be16818f56a485ab778c1

2020-07-08 sgrekhov@unipro.ru Fixes 797. LibTest\collection\HasNextIterator migrated to null safety
2020-07-08 sgrekhov@unipro.ru Fixes 796. LibTest\collection\IterableMixin migrated to null safety
2020-07-08 sgrekhov@unipro.ru Fixes 795. LibTest\collection\IterableBase migrated to null safety
2020-07-08 sgrekhov@unipro.ru Fixes 794. LibTest\collection\LinkedHashMap migrated to null safety
2020-07-08 sgrekhov@unipro.ru Fixes 792. LibTest\core\Map migrated to null safety
2020-07-08 sgrekhov@unipro.ru Fixes 791. LibTest\collection\Queue migrated to null safety
2020-07-08 sgrekhov@unipro.ru Fixes 789. LibTest\collection\HashMap migrated to null safety
2020-07-07 irina.arkhipets@gmail.com Fixed issue 790: LibTest\convert\Base64Encoder tests adopted to nnbd
2020-07-07 irina.arkhipets@gmail.com Fixed issue 790: LibTest\convert\Base64Codec tests adopted to nnbd
2020-07-07 irina.arkhipets@gmail.com Fixed issue 790: LibTest\convert\AsciiCodec tests adopted to nnbd
2020-07-07 irina.arkhipets@gmail.com Fixed issue 602: Added tests for least and greatest closure with nnbd.
2020-07-07 irina.arkhipets@gmail.com Fixed issue 785: Updated expected results for future flattening tests in nnbd-weak mode.
2020-07-07 sgrekhov@unipro.ru Fixes 788. LibTest\collection\DoubleLinkedQueueEntry migrated to null safety
2020-07-07 sgrekhov@unipro.ru Fixes 787. LibTest\collection\DoubleLinkedQueue migrated to null safety

https://github.com/dart-lang/sdk/issues/42584

Change-Id: I14d3ff4856296c66a403e1c1a9d767deb0af3f80
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/153604
Reviewed-by: William Hesse <a821cddceae7dc400f272e3cb1a72f400f9fed6d@google.com>
Reviewed-by: Nicholas Shahan <03847abd2d8aadfe859ecb98095a31f9f515dc47@google.com>

dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk