[🧹✨] Replace base::ResetAndReturn with std::move() in //content

Bug: 841899
Change-Id: Ie19782c08b5bc2612fd604f861fd311775e3d042
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1584844
Commit-Queue: Daniel Cheng <dcheng@chromium.org>
Auto-Submit: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#654284}
22 files changed