72901 Remove deprecated StatefulElement.inheritFromElement (cla: yes, framework, severe: API break, waiting for tree to go green)

72903 Remove deprecated Element methods (cla: yes, f: cupertino, f: material design, framework, severe: API break, waiting for tree to go green)

72904 improve error message when herocontroller is shared by multiple navig… (a: animation, a: error message, cla: yes, framework, waiting for tree to go green)

72922 fix a RenderSliverFixedExtentBoxAdaptor Exception  (cla: yes, framework, waiting for tree to go green)

72927 Improve Cupertino docs (cla: yes, f: cupertino, framework)

72930 Correct typos in RenderParagraph (cla: yes, framework, waiting for tree to go green)