Add example for move version of base::Passed.

The documentation only gave examples of calling base::Passed
with a pointer.

Change-Id: I86c516546b55e6dcd62f8c83cdff859cba64578d
Reviewed-on: https://chromium-review.googlesource.com/688685
Commit-Queue: Albert J. Wong <ajwong@chromium.org>
Reviewed-by: Albert J. Wong <ajwong@chromium.org>
Cr-Commit-Position: refs/heads/master@{#505808}
1 file changed