[graphite] Merge anonymous namespaces within DrawPass.cpp
[graphite] Merge anonymous namespaces within DrawPass.cpp

Change-Id: I25aba5427eab773ca85e5d2be789692c26b8c222
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/576578
Reviewed-by: Robert Phillips <95e8ac5504948c7bf91b22c16a8dbb7ae7c66bfd@google.com>
Commit-Queue: Michael Ludwig <cb1f3dd24de0f0b611b26bc28bec758a551d9b7d@google.com>

google/skia,google/skia,google/skia,google/skia,google/skia,google/skia,google/skia,google/skia,google/skia,google/skia