Use simple buffers instead of vectors

Start using simple buffers, these will be used for
multiple runs latter on.

Change-Id: Iab0559d5a47eb5e54254a985051d5d25a91be69f
Reviewed-on: https://skia-review.googlesource.com/140791
Commit-Queue: Herb Derby <herb@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
5 files changed