Capture/Replay: Make CaptureMidExecutionSetup param constant There is no need for for the context parameter to be non-constant. Bug: angleproject:7805 Change-Id: I1d998cf40f61a977ebce6d1160a859e082d99688 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4008198 Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Gert Wollny <gert.wollny@collabora.com>