26298 Cleanup toString transformer (cla: yes)

26299 Roll Skia from 1c4a0b89b0f6 to 2758a3189ade (3 revisions) (cla: yes, waiting for tree to go green)

26300 Roll Dart SDK from ff8dd0a9bbe1 to 3c595684faca (2 revisions) (cla: yes, waiting for tree to go green)

26302 Add support for compositing using Metal on macOS (cla: yes, platform-macos)

26303 Roll Skia from 2758a3189ade to 60e52284d55d (7 revisions) (cla: yes, waiting for tree to go green)