Allow the developer to pick either the GN or CMake build. Extract the lengthy string out to a new bash script in <dawn>/tools.
Windows CMake is TODO.
The Tint repo defaulted to using CMake, where as the Dawn repo defaulted to using GN. This gives us the best of both.
Bug: dawn:1339
Change-Id: Ibd5cf2a8f1c6d416b231d3267d68e006aee806be
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/86064
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Ben Clayton <bclayton@chromium.org>
feb42e5231