dawn: fix DawnCaps.cpp compile errors with webgpu

Bug: chromium:324422644
Change-Id: Ia15ef1254023a2a40c59f953c03e765fe1ee8a31
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/822028
Reviewed-by: Ben Wagner <bungeman@google.com>
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
Commit-Queue: Peng Huang <penghuang@chromium.org>
1 file changed