Use new capture calls to support offscreen mode.

Test: run_angle_perftests --gtest_filter="*Trace*"
Bug: angleproject:4845
Change-Id: I6d9ea79bd8339b7d5398e34b0407425e80ce1d32
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2327699Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>