Oilpan: fix gc_tracing compilation after r173313.

Expand the GCInfos for ListHashSet<> and ListHashSetNode<> to include
the required class name string when compiling with GC_TRACING enabled.

R=ager@chromium.org,haraken@chromium.org
BUG=

Review URL: https://codereview.chromium.org/271443004

git-svn-id: svn://svn.chromium.org/blink/trunk@173396 bbb929c8-8fbe-4397-9dbb-9b2b20218538