58530 [Line Heights] Add textHeightBehavior to SelectableText. (cla: yes, f: material design, framework, waiting for tree to go green)

58533 [flutter_tools] add flag for sound-null-safety, unify with experiments (a: null-safety, cla: yes, tool)

58535 Make _RenderSlider not be a semantics container (a: accessibility, cla: yes, f: focus, f: material design, framework)

58538 Don’t elapse real time during IOSDevice.startApp tests (cla: yes, team, tool, waiting for tree to go green)

58539 [flutter_tools] Allow the tool to suppress compilation errors. (cla: yes, tool)

58541 Fake out DeviceManager.getDevices in test (cla: yes, team, tool, waiting for tree to go green)