Remove SkDiscardableMemoryPool from public.bzl

SK_USE_DISCARDABLE_SCALEDIMAGECACHE is not defined in G3 (only Chrome
uses this?), so these files are not needed.

Change-Id: Ia2826c8f844e09011eb46d72c3743e89eaae18c2
Bug: skia:12541
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/585965
Reviewed-by: Ben Wagner <bungeman@google.com>
1 file changed