[minor] SkRemoteGlyphCache impl: add explicit

Change-Id: I3a1d97b867a66ed86e4c97bee72150b74d9dc112
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/249877
Reviewed-by: Hal Canary <halcanary@google.com>
Commit-Queue: Hal Canary <halcanary@google.com>
1 file changed