22541 Roll Skia from 5a89ed542f06 to ef8d52d8b2bb (3 revisions) (cla: yes, waiting for tree to go green)

22544 Roll Dart SDK from d67a5c245285 to 4bf74ee7d04e (2 revisions) (cla: yes, waiting for tree to go green)

22545 Check valid view_holder ptr before updating view (cla: yes, platform-fuchsia)

22546 Re-enable ShellTest.SkipAndSubmitFrame (cla: yes, waiting for tree to go green)

22548 Roll Skia from ef8d52d8b2bb to 396974683cbd (5 revisions) (cla: yes, waiting for tree to go green)