For highly dynamic data, which gets updated every frame, or almost
every frame, we're better off using our existing dynamic buffer
path. We could further optimize the dynamic buffer path by only
uploading changed data every frame.

BUG=angle:705

Change-Id: Icbb357b889be789b30f73067f75b13664c806929
Reviewed-on: https://chromium-review.googlesource.com/217280Tested-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Shannon Woods <shannonwoods@chromium.org>