CaptureMidExecutionSetup was accidentally creating a copy of a
vector, rather than using a const reference.

Test: Temple Run MEC on Android
Bug: b/152512564
Change-Id: Ia5eaa87235785eba7f10244d0ac7a831de0bcb0b
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2197282Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Cody Northrop <cnorthrop@google.com>