Re-land "D3D: Move some varying packing code into a new file." Re-land with fix for compile errors. Refactoring patch which moves code only. Work and full description will follow in a subsequent CL. BUG=angleproject:1202 Change-Id: Ib7c7dbd32491cdd9512dbecdc0e1e90303d8f28d Reviewed-on: https://chromium-review.googlesource.com/312481 Tryjob-Request: Jamie Madill <jmadill@chromium.org> Tested-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Corentin Wallez <cwallez@chromium.org>