Use simple buffers instead of vectors

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

Change-Id: I8dadbed036b7a60d708c49b84bb5e3bb3710f704
Reviewed-on: https://skia-review.googlesource.com/140578
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Herb Derby <herb@google.com>
5 files changed