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This callback can be called multiple times, so make it a
RepeatingCallback. Also pass it by value for functions that
take ownership per guidelines in //docs/callback.md.

Bug: 1007763
Change-Id: Ib15dd0a20357ac58dbe691b3dea263ebf24b0163
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1948364Reviewed-by: Guido Urdaneta <guidou@chromium.org>
Reviewed-by: danakj <danakj@chromium.org>
Commit-Queue: Matt Falkenhagen <falken@chromium.org>
Cr-Commit-Position: refs/heads/master@{#721180}