GitLab

This CL removed the unused delegate class for ImpressionHistoryTracker.

Bug: 965133
Change-Id: I0463a99f4dc7344c66533b4881fec5fe8fa6393a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1832711Reviewed-by: Hesen Zhang <hesen@chromium.org>
Commit-Queue: Xing Liu <xingliu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#702481}