Remove unused member function from art::Heap.
Remove unused member function from art::Heap.

Change-Id: I3f5417745cd7a3453bbbbd5159a5da79b2d44a16

treadstoneproject/artinst,treadstoneproject/artinst,treadstoneproject/artinst,treadstoneproject/artinst,treadstoneproject/artinst