Use incremental marking deque in idle notification.

BUG=

Review URL: https://codereview.chromium.org/766663006

Cr-Commit-Position: refs/heads/master@{#25564}
Remove deprecated pieces from generic algorithm.

R=titzer@chromium.org

Review URL: https://codereview.chromium.org/752263003

Cr-Commit-Position: refs/heads/master@{#25565}