ANGLE uses this extension instead of the Xlib extension.

Bug: angleproject:3876
Bug: b/140251624
Change-Id: I4bc420ddc340b8c35eca20d894718c8c3db68a3a
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/36148Reviewed-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Tested-by: Jamie Madill <jmadill@chromium.org>