There was no real reason to keep them in an angle directory and it makes
the generated projects nicer.

BUG=angleproject:981

Change-Id: I844e44dc5c2df51f5292cff4bdffe5e951745aae
Reviewed-on: https://chromium-review.googlesource.com/266871Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Brandon Jones <bajones@chromium.org>
Tested-by: Geoff Lang <geofflang@chromium.org>