25235 Roll Dart SDK from bc78a79e5e80 to c346bb2d834b (2 revisions) (cla: yes, waiting for tree to go green)

25236 Roll Skia from a6748aa80272 to c028c5c1f83e (2 revisions) (cla: yes, waiting for tree to go green)

25238 Roll Skia from c028c5c1f83e to c28336e5c272 (4 revisions) (cla: yes, waiting for tree to go green)

25241 [tracing] Add trace events for DartIsolate::HandleMessage (cla: yes)

25247 Highlight VSync support for embedders (cla: yes)