Fix cleanup bug in Docserver
Fix cleanup bug in Docserver

BUG=skia:
R=jcgregorio

Review URL: https://codereview.chromium.org/1736513004

google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot