Revert "Retain maps for several garbage collections"

This reverts commit 2bc756e4b36160595c811c5433d0238ae5192525
because of performance regression in kraken.

BUG=chromium:444232
LOG=N
TBR=hpayer@chromium.org

Review URL: https://codereview.chromium.org/816353002

Cr-Commit-Position: refs/heads/master@{#25918}