82564 Migrate to ChannelBuffers.push (a: tests, team, framework, f: material design, a: accessibility, cla: yes, f: cupertino, d: examples, waiting for tree to go green)

82843 refactor: Add MaterialStateMixin (severe: new feature, framework, f: material design, cla: yes, d: api docs, d: examples, a: quality, waiting for tree to go green, documentation)

82926 [web] Make web integration tests shadow DOM aware. (a: tests, team, framework, cla: yes, d: examples, waiting for tree to go green)

82939 FlutterDriver: deprecate enableAccessibility; redirect it to setSemantics; add setSemantics tests (a: tests, team, framework, cla: yes, d: examples)