* Name the platform thread in the timeline. This does not affect (nor is it affected by) the pthread name set by the embedder.
* Make it easier in the timeline to see not only when the frame was request, but also when that frame request was fulfilled.
* Trace message loop wakes.
* Namespaces have been updated to reflect the move from //flutter/sky/shell to //flutter/shell.
* shell/BUILD.gn file has been split into smaller GN files for each subcomponent of the shell (common, GPU, diagnostic, testing).
* GN dependencies have been rewritten to stop exposing common shell dependencies as public. Duplicates have also been removed.
* GPU subcomponent has been updated make it more suitable for Vulkan integration.
* The GLFW backend has been resurrected.
