Oilpan: switch some leftover raw references over to traced Member<>s.

R=haraken
BUG=340522

Review URL: https://codereview.chromium.org/1130793002

git-svn-id: svn://svn.chromium.org/blink/trunk@195035 bbb929c8-8fbe-4397-9dbb-9b2b20218538
6 files changed