Revert of Upstream Enhanced Bookmark Model

Revert of Upstream Enhanced Bookmark Model (patchset #6 id:100001 of https://codereview.chromium.org/899403002/)

Reason for revert:
This is blocking downstream and people are complaining.  I tried to land the downstream fix but there was a compile problem.

Sorry, hope you can fix the problems and re-land.

Original issue's description:
> Upstream Enhanced Bookmark Model
>
> This is the data layout of enhanced bookmark. There is no reason why
> this class should live in private repository.
>
> BUG=428832
>
> Committed: https://crrev.com/691b64f43fc0a69752344e5edbbc4d8f406cf261
> Cr-Commit-Position: refs/heads/master@{#315939}

TBR=kkimlabs@chromium.org,newt@chromium.org,cjhopman@chromium.org,ianwen@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=428832
Committed: https://crrev.com/f40cb64710a333da6d554e98dfcc432cd6cf8f1f
Cr-Commit-Position: refs/heads/master@{#315976}

[alex clarke (OOO till 29th), 2015-02-12 14:51:43]

Created Revert of Upstream Enhanced Bookmark Model

[commit-bot: I haz the power, 2015-02-12 14:52:13]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/920043003/1

[alex clarke (OOO till 29th), 2015-02-12 14:52:14]

alexclarke@chromium.org changed reviewers:
+ miguelg@chromium.org

[commit-bot: I haz the power, 2015-02-12 14:52:48]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-02-12 14:53:40]

Patchset 1 (id:??) landed as
https://crrev.com/f40cb64710a333da6d554e98dfcc432cd6cf8f1f
Cr-Commit-Position: refs/heads/master@{#315976}