19993 [fuchsia] Adds a test for clock change (cla: yes)

20003 Reland: Avoid a copy in EncodeImage (cla: yes, perf: speed, severe: performance)

20005 4x4.png -> 2x2.png; this file is actually 2x2 (cla: yes)

20006 Improve FlRenderer interface in preperation for Wayland on Linux (cla: yes)

20008 [web] Address platform changes in the integration tests. Part 1 (cla: yes)

20010 [null-safety] fix real failures (cla: yes)

20011 remove usage of dartdev command (cla: yes)

20013 Add purge-persistent-cache (cla: yes)