Revert "Switch to 8.1 SDK and d3dcompiler_47.dll"

This reverts commit e1425d95ba0ab095c5d64536bbeb3f78adcbf79f.

This is to keep the GPU fyi bots green until the chrome side is landed. Chrome will be rolling to e1425d95...

Change-Id: Iff1c60eeb7143fb72afa8525b31f8f0de9385897
Reviewed-on: https://chromium-review.googlesource.com/229497
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Tested-by: Jamie Madill <jmadill@chromium.org>