This reverts commit 28394c22.

Reason for revert: may be the cause of flakiness on Win10 Debug (NVIDIA) per http://crbug.com/972914 .

Original change's description:
> Revert "Temporarily disable creating D3D debug device."
> 
> This reverts commit 3d544fff.
> 
> Reason for revert: Seems like flakiness is not related.
> 
> Suppress D3D11 test failures uncovered by re-enabling D3D debug device:
> ComputeShaderTest.DispatchCompute
> Texture2DTestES3.TextureImplPropogatesDirtyBits
> D3DTextureTestMS.*
> 
> Also a small fix to ANGLETestBase::checkD3D11SDKLayersMessages
> to clear reported messages, otherwise the failures are also reported
> for tests following the one with the actual failure.
> 
> Original change's description:
> > Temporarily disable creating D3D debug device.
> >
> > To diagnose whether Windows Intel end2end tests flakiness
> > is related to creating debug device and new version of Windows SDK.
> >
> > Bug: angleproject:3153
> > Change-Id: Ica7eae3fe875e22203b6dfd98b83604d66a97737
> > Reviewed-on: https://chromium-review.googlesource.com/c/1476954
> > Reviewed-by: Geoff Lang <geofflang@chromium.org>
> > Commit-Queue: Yuly Novikov <ynovikov@chromium.org>
> 
> Bug: angleproject:3153, angleproject:3493
> Bug: angleproject:3501, angleproject:3512, angleproject:3513
> 
> Change-Id: I232da72aa09c2b9230cf179dd54e1731f8365f8e
> Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1480854
> Reviewed-by: Yuly Novikov <ynovikov@chromium.org>
> Reviewed-by: Jamie Madill <jmadill@chromium.org>
> Commit-Queue: Yuly Novikov <ynovikov@chromium.org>

TBR=ynovikov@chromium.org,geofflang@chromium.org,jmadill@chromium.org

Change-Id: I38a5cc9bb6ebcd50e97e40cc972a82679e73732a
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: angleproject:3153, angleproject:3493, angleproject:3501, angleproject:3512, angleproject:3513
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1652784Reviewed-by: Kenneth Russell <kbr@chromium.org>
Commit-Queue: Kenneth Russell <kbr@chromium.org>