[graphite] Use SkTArray instead of std::vector to store DrawPasses

This aligns how DrawPass instances and DispatchGroup instances are
stored following code review feedback in review.skia.org/644560.

Change-Id: I9aeff18baf73e75e590c9cf0ed399fbe706643be
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/656517
Commit-Queue: Arman Uguray <armansito@google.com>
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
11 files changed