This CL adds the DEPS entry to checkout `clang-tidy` if requested
in the `.gclient` config file. A doc is added which gives some
guidance on how to run `clang-tidy`.
Change-Id: I92eeaff33137158ffd17315649fb333c366fc91d
Bug: dawn:1414
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/89801
Auto-Submit: Dan Sinclair <dsinclair@chromium.org>
Reviewed-by: Ben Clayton <bclayton@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>