Revert of Stop passing raw pointers to base::Value API in c/b/ui (patchset #5 id:80001 of https://codereview.chromium.org/2812953002/ )

Reason for revert:

Findit(https://goo.gl/kROfz5) identified CL at revision 464860 as the
culprit for failures in the build cycles as shown on:
https://findit-for-me.appspot.com/waterfall/culprit?key=ag9zfmZpbmRpdC1mb3ItbWVyRAsSDVdmU3VzcGVjdGVkQ0wiMWNocm9taXVtLzRhYWM0NzFjYzczOTQyNDliMWEzZDMyYTc3N2QwNTM5YzJhZTU0ZDUM

Original issue's description:
> Stop passing raw pointers to base::Value API in c/b/ui
>
> Passing ownership of base::Value into API methods DictionaryValue::Set,
> DictionaryValue::SetWithoutPathExpansion, and ListValue::Set through raw
> pointers is deprecated, can hide bugs and should be done via unique_ptr
> instead.
>
> Therefore, this CL migrates c/b/ui to use the unique_ptr-based API.
>
> BUG=581865
> TBR=dbeam@chromium.org
>
> Review-Url: https://codereview.chromium.org/2812953002
> Cr-Commit-Position: refs/heads/master@{#464860}
> Committed: https://chromium.googlesource.com/chromium/src/+/4aac471cc7394249b1a3d32a777d0539c2ae54d5

TBR=derat@chromium.org,estade@chromium.org,jdoerrie@chromium.org,msw@chromium.org,dpapad@chromium.org,dbeam@chromium.org,vabr@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=581865

Review-Url: https://codereview.chromium.org/2820823005
Cr-Commit-Position: refs/heads/master@{#464867}
61 files changed