28537 Reland “Shader warm up (#27660)” (cla: yes, framework, severe: performance)

28540 Add animation curve slowMiddle (a: animation, cla: yes, framework, severe: new feature)

28546 Call onTapCancel when down pointer gets cancelled (cla: yes, f: gestures, framework)

28555 disable dart2js test (a: tests, cla: yes, team)

28558 Fix typo (a: text input, cla: yes, d: api docs, f: material design)

28597 Adjust remaining Cupertino route animations to match native (a: fidelity, cla: yes, f: cupertino, f: routes, waiting for tree to go green)

28598 TextField Snippet for API Docs (cla: yes)