Workaround clear issue on Intel Skylake D3D driver On some Intel D3D drivers on Skylake, calling clear may take no effect. To work around this bug, we call clear() twice when we attempt to do clear on these platforms. BUG=chromium:655534 Change-Id: I3b05892e80e5797d268861e8f52e080f5175855b Reviewed-on: https://chromium-review.googlesource.com/398522 Commit-Queue: Geoff Lang <geofflang@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org>