Remove non-negative offsets restriction in D3D extension The EGL_ANGLE_d3d_texture_client_buffer extension currently fails if either EGL_TEXTURE_OFFSET_[X|Y]_ANGLE offsets are negative. This restriction is unnecessary, as D3D allows for negative offsets. Bug: angleproject:7446 Change-Id: I2e258a3a558eae51794f6533e28a0c06532f156d Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3715956 Commit-Queue: Rafael Cintron <rafael.cintron@microsoft.com> Reviewed-by: Rafael Cintron <rafael.cintron@microsoft.com> Reviewed-by: Geoff Lang <geofflang@chromium.org>