how to find possible candidates:

find . -name *.cxx | grep -v compilerplugins > cxx.list
for i in `cat cxx.list`; do basename $i .cxx; done > cxx.base.list
for i in `cat cxx.base.list | sort -u`; do echo $(git grep -w $i -- '*.mk' | wc -l) $i; done > cxx.count

Change-Id: I15c6cc7195e58d79967388850a0c90b915b001b7