68644 Fix overscroll edge case that puts NestedScrollViews out of sync (cla: yes, f: scrolling, framework, severe: regression, waiting for tree to go green)

69063 Add horizontal gesture support for CupertinoScrollbar (a: desktop, a: quality, cla: yes, f: cupertino, f: scrolling, framework, waiting for tree to go green)

69795 Default Keyboard ScrollActions with PrimaryScrollController (a: desktop, cla: yes, f: cupertino, f: focus, f: material design, f: scrolling, framework, platform-web, severe: new feature, waiting for tree to go green)

70401 Re-land ‘Default Keyboard ScrollActions with PrimaryScrollController’ (a: desktop, cla: yes, f: cupertino, f: focus, f: material design, f: scrolling, framework, platform-web, severe: new feature)