Oilpan: use transition types instead of Node RefPtrs for Range and
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R=haraken@chromium.org, oilpan-reviews@chromium.org, sigbjornf@opera.com
BUG=357163

Review URL: https://codereview.chromium.org/316563002

git-svn-id: svn://svn.chromium.org/blink/trunk@175371 bbb929c8-8fbe-4397-9dbb-9b2b20218538