New a11y traversal:
- sort direct sibling SemanticsNodes only
- use new sorting algorithm
- implement RTL
- test semantics in traversal order by default
- add AppBar traversal test
- breaking: remove nextNodeId/previousNodeId from the framework
- breaking: remove DebugSemanticsDumpOrder.geometricOrder
This chip demo is more interactive than the last one, trying to exercise all of the types of chips for a demo that lets you select different types of "chips" (like tortilla, wood, micro, etc.), and then filter them and select an action on them.
Changes since last roll:
```
ed303c628 Roll dart sdk again. Previous roll required 23ae4fa098 revert. (#4966)
8cd272733 Revert "Roll dart to 7764e6962e22afcf4b58c4e3cef3147330f3c884. (#4960)" (#4965)
9199b40f2 Revert "Support multiple shells in a single process. (#4932)" (#4964)
6baff4c82 Support multiple shells in a single process. (#4932)
31c5bb427 Roll dart to 7764e6962e22afcf4b58c4e3cef3147330f3c884. (#4960)
c8e4c6984 Avoid copying the contents of large platform message responses (#4947)
5ff527295 Update to use new vulkan GrBackendRenderTarget ctor. (#4962)
0c8993a1a Update to use new vulkan GrBackendRenderTarget ctor (part 2) (#4963)
132ebdda8 Revert "Roll src/third_party/skia/ 9874bf1bc..52e16d984 (135 commits) (#4958)" (#4961)
11882ab9e Roll src/third_party/skia/ 9874bf1bc..52e16d984 (135 commits) (#4958)
```
Add consts
* Revert "Roll engine to 6473f1b106485cb0b4ea569af383173daeef8895 (#16032)"
This reverts commit 844ced010a.
* Revert "Let travis test archiving per commit too (#16004)"
This reverts commit df5905f382.
Adds a package that will support connecting to and debugging devices with multiple instances of the Dart VM, and operate on multiple Isolates and Flutter Views.
Currently supports connecting to all existing Dart VMs and extracting information about all Flutter Views running across each VM.
This is not a grand refactor yet, it's just cleaning up what we have
already, so that people who keep using this API (e.g. dialogs) have
something coherent to deal with.
The major changes are that Navigator and NavigatorState have the same
API now, that most of the examples use `<void>` instead of `<Null>`,
that the navigator observer can see replaces, and that the `settings`
is moved from ModalRoute to Route. I also cleaned up some of the API
documentation.
* use HttpOverrides and dart:io HttpClient in flutter
* add missing package:http dependency
* update flutter packages and remove comment about createHttpClient from flutter_test
* move byte loading logic to common class, move string parsing logic to base class
* addAll doesn't work for a Uint8List
* use bytes.setRange
* undo addition to hello_world
* add newline to end of binding.dart
* and a newline for hello world
* refactor to function and add tests
* address comments on unknown length case
* alignment
* sort alaphabetically
* rename convertResponse to consolidateClientHttpClientResponseBytes. Add header
* fix alignment in test
