GitLab

Keep GetTiles as async call but return the copies of tile data.

Bug: 1066550
Change-Id: I0b2eddd7063c5f6ded269c4223cd3e67da2aedf8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2161479
Commit-Queue: Hesen Zhang <hesen@chromium.org>
Auto-Submit: Hesen Zhang <hesen@chromium.org>
Reviewed-by: David Trainor <dtrainor@chromium.org>
Reviewed-by: Shakti Sahu <shaktisahu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#763534}