Remove unused class WorkingSetInformationBuffer

Change-Id: I0ff4dbdf64ae3d2176a2e5bd1afe0ed353ebe223
Reviewed-on: https://chromium-review.googlesource.com/c/1343559
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Xi Cheng <chengx@chromium.org>
Cr-Commit-Position: refs/heads/master@{#611023}
1 file changed