GitLab

This reverts
https://chromium-review.googlesource.com/c/chromium/src/+/2626687
as Impression::impression_data is initialized due to
https://chromium-review.googlesource.com/c/chromium/src/+/2625293

Bug: 1165985
Change-Id: I6dbcb17c9f1f31487e2f1ba3b2da6febd906a8ce
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2627190
Auto-Submit: Eric Willigers <ericwilligers@chromium.org>
Commit-Queue: John Delaney <johnidel@chromium.org>
Reviewed-by: John Delaney <johnidel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#843660}