Version 4.3.61.21 (cherry-pick)

Merged 31994391

Insert a filler at the new space top even if the top is at the limit.

BUG=chromium:470390
LOG=N
TBR=jarin@chromium.org

Review URL: https://codereview.chromium.org/1134293002

Cr-Commit-Position: refs/branch-heads/4.3@{#25}
Cr-Branched-From: f5c0a23a-refs/heads/4.3.61@{#1}
Cr-Branched-From: 0a7d4f49-refs/heads/master@{#27508}