preprocessor: Miscellaneous cleanups - Use full header paths in includes - Use ASSERT instead of assert - Use angle::NonCopyable instead of PP_DISALLOW_COPY_AND_ASSIGN - Use range-for in a couple places - Remove pp_utils.h BUG=angleproject:1522 Change-Id: If107fef89e8465bca65cf664926d1051c5d1e232 Reviewed-on: https://chromium-review.googlesource.com/387212 Commit-Queue: Corentin Wallez <cwallez@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org>