13192 Use window.devicePixelRatio in the CanvasKit backend

13193 Custom compositor layers must take into account the device pixel ratio.

13196 Document //flutter/runtime/dart_snapshot.h

13207 Wrap the text in text editing to fix selections.

13209 Preserve stdout colors of subprocesses run by felt

13212 Add trace events around custom compositor callbacks.

13218 Specify a human readable reason for an error from the embedder API.

13232 Avoid dereferencing IO manager weak pointers on the UI thread

13237 Do not attempt to drain the SkiaUnrefQueue in the destructor

13238 Allow embedders to update preferrred locales.