Fix dxva_video_decode_accelerator.cc to compile with Win 10 SDK

Fix dxva_video_decode_accelerator.cc to compile with Win 10 SDK

dxva_video_decode_accelerator.cc defines CLSID_VideoProcessorMFT,
and so does mfidl.h in the Windows 10 SDK. This change uses
VER_PRODUCTBUILD to detect the SDK version so that this source
file can build with the Windows 8.1 and Windows 10 SDKs.

R=dalecurtis@chromium.org
BUG=491424
Committed: https://crrev.com/3ab481ec3953f63cfc1ec066eafd788d061f7834
Cr-Commit-Position: refs/heads/master@{#339505}

[DaleCurtis, 2015-07-20 18:46:49]

lgtm

[brucedawson, 2015-07-20 20:08:00]

The CQ bit was checked by brucedawson@chromium.org

[commit-bot: I haz the power, 2015-07-20 20:08:38]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1244883002/1

[commit-bot: I haz the power, 2015-07-20 20:30:36]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-07-20 20:31:37]

Patchset 1 (id:??) landed as
https://crrev.com/3ab481ec3953f63cfc1ec066eafd788d061f7834
Cr-Commit-Position: refs/heads/master@{#339505}