Use more consistent naming for caching methods in NodeListsNodeData class

All the caching methods are now called addCache() / removeCache() / cached()
and overloading is used. The naming used to be a bit confusing, especially
for the addCacheWithAtomicName() method which was not taking an AtomicString
in argument.

R=eseidel, adamk

Review URL: https://codereview.chromium.org/138343007

git-svn-id: svn://svn.chromium.org/blink/trunk@166869 bbb929c8-8fbe-4397-9dbb-9b2b20218538