Merge "surfaceflinger: fix missing pure virtual declarations." am: f4e70632 am: d7a7f995

Original change: https://android-review.googlesource.com/c/platform/frameworks/native/+/2392152



Change-Id: I437e66f4d40997cdf92a553313bc1c0f3fdbbe2a
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>