
Avoid retaining tons of memory on the finalizer due to retained backrefs

R=johnlenz,nicksantos
DELTA=4  (0 added, 2 deleted, 2 changed)


Revision created by MOE tool push_codebase.
MOE_MIGRATION=5420


git-svn-id: 818616af560c21f974e3119d89e3310384da871a@2161 b0f006be-c8cd-11de-a2e8-8d36a3108c74

weitzj/closure-compiler,weitzj/closure-compiler