[sf] Properly update clones of clones

When updating a cloned layer hierarchy that contains
another cloned layer hierarchy, we are dependent on
the order in which we update each hierarchy.
The inner cloned hierarchy must be updated first
otherwise the outer clone will not capture the entire
tree and some layers might be omitted from
composition.
To fix this we track all layer mirror roots. When updating
each root, we check to see if they mirror another root. If
they do mirror another root and that root has not been updated,
we update the root again at the end.

Test: repro steps in bug
Fixes: 279622227
Change-Id: I07e3f2c89d62d44455fda9fe3f8203215c22abf7
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index fffd63a..6855562 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -296,8 +296,7 @@
     // the client can no longer modify this layer directly.
     void onHandleDestroyed(BBinder* handle, sp<Layer>& layer, uint32_t layerId);
 
-    // TODO: Remove atomic if move dtor to main thread CL lands
-    std::atomic<uint32_t> mNumClones;
+    std::vector<Layer*> mLayerMirrorRoots;
 
     TransactionCallbackInvoker& getTransactionCallbackInvoker() {
         return mTransactionCallbackInvoker;