Refactor buffer existance check into Buffer::invalidateStaticData. Change-Id: I28a7654d152865c236831636f00554a71784667b Reviewed-on: https://chromium-review.googlesource.com/184394 Reviewed-by: Shannon Woods <shannonwoods@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org> Tested-by: Geoff Lang <geofflang@chromium.org>